Merge remote-tracking branch 'remotes/stsquad/tags/pull-build-test-20160209' into...

Merge remote-tracking branch 'remotes/stsquad/tags/pull-build-test-20160209' into staging

This is the third attempt for this pull request.

Since the v4 was posted:
 - fixed merge conflict with ed7f5f1d8db06fc31352a5ef4f54985e630c575a
 - added cleaner separation line to MAINTAINERS at Fam's request
 - skip "make check" for --enable-trace-backends=simple (see 41fc57e44ed)

# gpg: Signature made Tue 09 Feb 2016 12:33:45 GMT using RSA key ID 5A9E2A44
# gpg: Good signature from "Alex Bennée (Master Work Key) <alex.bennee@linaro.org>"

* remotes/stsquad/tags/pull-build-test-20160209:
  MAINTAINERS: Add .travis.yml
  .travis.yml: reduce the test matrix a little
  .travis.yml: enable ccache for the builds
  .travis.yml: enable each of the co-routine backends
  .travis.yml: run make check for all matrix targets
  .travis.yml: migrate to container builds

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>