Add make cover command

[generalhenry]

closes #371

added make cover command

to test:

make test (to verify no regression)
make cover (to run tests with coverage)

[freignat91]

LGTM

[subfuzion]

I didn't actually have a successful outcome running this, but it has to do with tests failing, not the PR itself:

amp (unit-coverage)$ make cover
echo "mode: count" > coverage-all.out
go test -coverprofile=coverage.out -covermode=count github.com/appcelerator/amp/api/rpc/service; tail -n +2 coverage.out >> coverage-all.out;  go test -coverprofile=coverage.out -covermode=count github.com/appcelerator/amp/data/storage/etcd; tail -n +2 coverage.out >> coverage-all.out;  go test -coverprofile=coverage.out -covermode=count github.com/appcelerator/amp/api/rpc/stack; tail -n +2 coverage.out >> coverage-all.out;  go test -coverprofile=coverage.out -covermode=count github.com/appcelerator/amp/data/influx; tail -n +2 coverage.out >> coverage-all.out;  go test -coverprofile=coverage.out -covermode=count github.com/appcelerator/amp/api/rpc/stats; tail -n +2 coverage.out >> coverage-all.out;  go test -coverprofile=coverage.out -covermode=count github.com/appcelerator/amp/api/rpc/topic; tail -n +2 coverage.out >> coverage-all.out;  go test -coverprofile=coverage.out -covermode=count github.com/appcelerator/amp/api/rpc/logs; tail -n +2 coverage.out >> coverage-all.out;
ok      github.com/appcelerator/amp/api/rpc/service     2.105s  coverage: 53.2% of statements
ok      github.com/appcelerator/amp/data/storage/etcd   2.567s  coverage: 72.0% of statements
ok      github.com/appcelerator/amp/api/rpc/stack       13.142s coverage: 53.5% of statements
ok      github.com/appcelerator/amp/data/influx 0.022s  coverage: 52.6% of statements
ok      github.com/appcelerator/amp/api/rpc/stats       1.096s  coverage: 73.8% of statements
ok      github.com/appcelerator/amp/api/rpc/topic       67.157s coverage: 55.6% of statements
2016/11/03 10:53:55 Waiting for swarm to be ready
2016/11/03 10:53:55 connecting to etcd at http://127.0.0.1:2379
2016/11/03 10:53:55 connecting to etcd at http://127.0.0.1:2379
2016/11/03 10:53:55 connected to etcd at http://127.0.0.1:2379
2016/11/03 10:53:55 connecting to elasticsearch at http://127.0.0.1:9200
2016/11/03 10:53:55 connected to etcd at http://127.0.0.1:2379
2016/11/03 10:53:55 connecting to elasticsearch at http://127.0.0.1:9200
2016/11/03 10:53:55 connected to elasticsearch at http://127.0.0.1:9200
2016/11/03 10:53:55 Connecting to NATS-Streaming at nats://127.0.0.1:4222
2016/11/03 10:53:55 connected to elasticsearch at http://127.0.0.1:9200
2016/11/03 10:53:55 Connecting to NATS-Streaming at nats://127.0.0.1:4222
2016/11/03 10:53:55 Connected to NATS-Streaming at nats://127.0.0.1:4222
2016/11/03 10:53:55 connecting to InfluxDB at http://127.0.0.1:8086
2016/11/03 10:53:55 connected to influxDB at http://127.0.0.1:8086
2016/11/03 10:53:55 connecting to Docker API at unix:///var/run/docker.sock version API: 1.24
2016/11/03 10:53:55 connected to Docker at unix:///var/run/docker.sock
2016/11/03 10:53:55 Connecting to amplifier
2016/11/03 10:53:55 Connected to NATS-Streaming at nats://127.0.0.1:4222
2016/11/03 10:53:55 connecting to InfluxDB at http://127.0.0.1:8086
2016/11/03 10:53:55 connected to influxDB at http://127.0.0.1:8086
2016/11/03 10:53:55 connecting to Docker API at unix:///var/run/docker.sock version API: 1.24
2016/11/03 10:53:55 connected to Docker at unix:///var/run/docker.sock
2016/11/03 10:53:55 amplifier is listening on port 50101
2016/11/03 10:53:56 Connected to amplifier
2016/11/03 10:53:57 log requested: [service:"c8f84c9baa823e7d5938c41537d49917c03372e8e835c023bfd2507e27fc055c" ]
2016/11/03 10:53:58 log requested: [service:"c8f84c9baa823e7d5938c41537d49917c03372e8e835c023bfd2507e27fc055c" ]
2016/11/03 10:53:59 log requested: [service:"c8f84c9baa823e7d5938c41537d49917c03372e8e835c023bfd2507e27fc055c" ]
2016/11/03 10:54:00 log requested: [service:"c8f84c9baa823e7d5938c41537d49917c03372e8e835c023bfd2507e27fc055c" ]
2016/11/03 10:54:01 log requested: [service:"c8f84c9baa823e7d5938c41537d49917c03372e8e835c023bfd2507e27fc055c" ]
.... hundreds of lines ....
2016/11/03 10:55:20 log requested: [service:"c8f84c9baa823e7d5938c41537d49917c03372e8e835c023bfd2507e27fc055c" ]
2016/11/03 10:55:20 log requested: []
2016/11/03 10:55:20 log requested: []
2016/11/03 10:55:20 log requested: [container:"4b9b6f98c1ff1412da25a7ff8e969b21ef4e4d5ae07fd84133625775ee53f15e" ]
2016/11/03 10:55:20 log requested: []
2016/11/03 10:55:20 log requested: [node:"82b1b21e48bd1a02a4a934a71427a9151cf335d1b1c08734c73e7af82f29675c" ]
2016/11/03 10:55:20 log requested: [service:"c8f84c9baa823e7d5938c41537d49917c03372e8e835c023bfd2507e27fc055c" ]
2016/11/03 10:55:20 log requested: [service:"testServiceName" ]
--- FAIL: TestShouldFilterByService (0.03s)
        Error Trace:    logs_test.go:145
        Error:          Should NOT be empty, but was []
        Messages:       We should have at least one entry

2016/11/03 10:55:20 log requested: [message:"test" ]
2016/11/03 10:55:20 log requested: [stack:"196aeef6ee66f6510d5f3b872ee401090d6e55ff4ce082426911d769c6375d16" ]
2016/11/03 10:55:20 log requested: [stack:"testStackName" ]
--- FAIL: TestShouldFilterByStack (0.03s)
        Error Trace:    logs_test.go:176
        Error:          Should NOT be empty, but was []
        Messages:       We should have at least one entry

2016/11/03 10:55:20 log requested: [size:1 ]
2016/11/03 10:55:20 log requested: [size:11 ]
2016/11/03 10:55:20 log requested: [size:21 ]
2016/11/03 10:55:20 log requested: [size:31 ]
2016/11/03 10:55:20 log requested: [size:41 ]
2016/11/03 10:55:20 log requested: [size:51 ]
2016/11/03 10:55:20 log requested: [size:61 ]
2016/11/03 10:55:20 log requested: [size:71 ]
2016/11/03 10:55:20 log requested: [size:81 ]
2016/11/03 10:55:20 log requested: [size:91 ]
2016/11/03 10:55:20 log stream requested: []
2016/11/03 10:55:20 log stream requested: [container:"4b9b6f98c1ff1412da25a7ff8e969b21ef4e4d5ae07fd84133625775ee53f15e" ]
2016/11/03 10:55:21 log stream requested: [node:"82b1b21e48bd1a02a4a934a71427a9151cf335d1b1c08734c73e7af82f29675c" ]
2016/11/03 10:55:21 log stream requested: [service:"testService" ]
2016/11/03 10:55:21 log stream requested: [message:"test message " ]
2016/11/03 10:55:21 log stream requested: [message:"TEST MESSAGE " ]
2016/11/03 10:55:21 log stream requested: [stack:"testStack" ]
FAIL
coverage: 78.2% of statements
FAIL    github.com/appcelerator/amp/api/rpc/logs        86.272s
go tool cover -html=coverage-all.out

It would be good if we could filter out autogenerated files (ie, *.pb.go), but in any case the make cover command works well. 👍