Updates for Travis CI

[miabbott]

• Use the new Docker based infrastructure (sudo: false)
• Add the other valid feature directory (atomic) to dry-run test
• Add the fancy Travis badge to README.md

Signed-off-by: Micah Abbott miabbott@redhat.com

[miabbott]

@aweiteka Travis already doing work for us. Found problems in the features/atomic/smoketest.feature file.

Could you have a look at this PR (build errors are not related) and merge?