Use jME 3.7 stable

gradle.properties

@@ -3,7 +3,7 @@ jmeVersion = 3.7.0
 # Version used for application and settings folder, no spaces!
 jmeMainVersion = 3.7
 # Version addition pre-alpha-svn, Stable, Beta
-jmeVersionTag = beta1.2.2
+jmeVersionTag = stable
 # Increment this each time jmeVersionTag changes but jmeVersion stays the same
 #jmeVersionTagID = 0