grammar mistake in exception message.
Merge branch 'master' of github.com:geb/geb

Conflicts:
	module/geb-core/src/main/groovy/geb/content/NavigableSupport.groovy
Update to new spock unroll syntax.
Add Travis CI build descriptor.
Add build status img to the readme.
Add build status img to the readme.
Try running the travis build through tee so we can see what's happening.
Fix test.