Add July 2014 VM update announcement

The Android update shall be coordinated with the [documentation update](https://github.com/travis-ci/docs-travis-ci-com/pull/91).
If it's indeed released tomorrow (what time?) and I can get the cookbooks updated and the VM images made, then there is a good chance they can be included in the update.

I'll need to consult @joshk how we actually go about carrying this out, so the target date may move still.