Switch go builds from epel-testing to epel stable

[alexeykazakov]

We need to switch all our go repos from using go from epel-testing to epel (stable)

• Core services
• Build services
• Work Item Tracker and App creation services
• Che OSIO (if any)?...

[alexeykazakov]

cc: @pbergene @sbose78 @sunilk747 @chmouel @ibuziuk

[corinnekrych]

@alexeykazakov maybe it would be nice to move to goa 1.4 to be able to use golangv1.11, see comment fabric8-services/build-tool-detector#28 (comment)
wdyt?

[alexeykazakov]

@corinnekrych absolutely. We are planning to investigate goa 1.4 move in our cluster service - fabric8-services/fabric8-cluster#13
Cluster service is tiny and looks like a good candidate for the first try.
But this is not a blocker for using go 1.11 - fabric8-services/build-tool-detector#28 (comment)