changed version number to 0.9.15
updated version
implemented that the xcode version can also be specifed with the version nummber
Merge branch 'master' into develop

Conflicts:
	README.md
	plugin/build.gradle
updated that the output of xcode 6.1.1 works that has ansi colors
added better output if the unit tests failed
archive task now creates a xcarchive bundle: issue #1