Add golang source detector for new-app

Adding golang source detector for oc new-app,
looks for main.go and Godeps

Fixes issue #12417

examples/gitserver/hooks/detect-language

@@ -65,4 +65,9 @@ if has project.json || hasglob '*.csproj'; then
   exit 0
 fi
 
+if has main.go Godeps; then
+  echo "${prefix}golang"
+  exit 0
+fi
+
 exit 1

pkg/generate/source/detector.go

@@ -27,6 +27,7 @@ var DefaultDetectors = Detectors{
 	DetectScala,
 	DetectDotNet,
 	DetectLiteralDotNet,
+	DetectGolang,
 }
 
 // DetectRuby detects Ruby source
@@ -74,6 +75,11 @@ func DetectLiteralDotNet(dir string) *Info {
 	return detect(".net", dir, "project.json", "*.csproj")
 }
 
+// DetectGolang detects Go source
+func DetectGolang(dir string) *Info {
+	return detect("golang", dir, "main.go", "Godeps")
+}
+
 // detect returns an Info object with the given platform if the source at dir contains any of the argument files
 func detect(platform string, dir string, globs ...string) *Info {
 	for _, g := range globs {