Revert "move truffle tests out of the test/pom.rb to avoid installing test gems"

This reverts commit 01d56f3f67b9f774da87d4c1d455345abe4d46b8.

Conflicts:
	lib/pom.rb
	lib/pom.xml
	pom.rb
	pom.xml
fixed snapshot version in core/pom.rb - not only in pom.xml
remove obsolete gems
Merge branch 'master' of jruby.org:jruby