Adding integration test framework along with 3 tests.

These tests are similar to Go unit tests except that they're targetting
tesing of a running cAdvisor client. They do this by interacting with
the testing framework that is able to talk to the running cAdvisor. This
cAdvisor could be local or remote.
Merge pull request #317 from vmarmol/integration

Adding integration test framework along with 3 tests.