The integration test script was changed so that it aborts the testing
when the cAdvisor binary exits with a non-zero error code.
Also in this PR:
- clean up makefile to print more informative output
- change make release to build the release binary
- Poll localhost:8080/healthz to wait for cAdvisor to start
- Set the script exit code to the test exit status
- Fix bash formatting
- Check for sudo access at the start
