PLT-1800 Load server side locale from the config.json (#3135)

* PLT-1800 Load server side locale from the config.json

* Add support for locales with country specifics

* Fix localization on served locale file as plain/text

* Remove github.com/cloudfoundry/jibber_jabber as vendor dependency

utils/config_test.go

@@ -9,5 +9,5 @@ import (
 
 func TestConfig(t *testing.T) {
 	LoadConfig("config.json")
-	InitTranslations()
+	InitTranslations(Cfg.LocalizationSettings)
 }