Bumped goomph to 3.0.4, which fixes #4.

 The test mac machine had gotten into a weird state, not sure how. Wiping test machine's ~/.goomph directory made it possible to reproduce the reported issue, and fixing it also fixed the underlying problem with PDE build generating bad .app folders.

Author: nedtwigg

gradle.properties

@@ -7,7 +7,7 @@ org=diffplug
 
 # Build requirements
 VER_JAVA=1.8
-VER_GOOMPH=3.0.3
+VER_GOOMPH=3.0.4
 VER_BND_PLATFORM=1.4.0
 
 # The version of PDE (and eclipse platform plugins)