[FLOC-4447] Add google-compute-engine as a requirement

[wallrj]

Fixes: https://clusterhq.atlassian.net/browse/FLOC-4447

This is caused by:

• On new debian 8 installs using google_compute_engine virtualenv installed boto is broken GoogleCloudPlatform/compute-image-packages#262
• Update README for boto troubleshooting. GoogleCloudPlatform/compute-image-packages#263

I've added google-compute-engine package here but in re-running the admin/update-requirements tool I've pulled in a few other library upgrades and a new version of setuptools.
All good stuff I'm sure and all the tests still pass.

I had some trouble with the GCE functional tests:

• http://ci-live.clusterhq.com:8080/job/ClusterHQ-flocker/job/google-compute-engine-FLOC-4447/job/_run_trial_for_gce_storage_driver_on_CentOS_7_flocker.node.agents.functional/
• http://ci-live.clusterhq.com:8080/job/ClusterHQ-flocker/job/google-compute-engine-FLOC-4447/job/_run_trial_for_gce_storage_driver_on_Ubuntu_trusty_flocker.node.agents.functional/

But that turned out be the fault of the old version of virtualenv installed on our static GCE slaves.

I manually upgraded pip and virtualenv as the jenkins user on those slaves.

We should really update the VM images too, but this works for now.
(as discussed with @sarum90 a week or two ago)

[myechuri]

@wallrj : can you please confirm that all the other (non google-compute-engine) package version updates are unrelated? Thanks!

Accepted the issue, please go ahead with the merge, thanks for making the changes!

[wallrj]

Thanks @myechuri for the review.

@wallrj : can you please confirm that all the other (non google-compute-engine) package version updates are unrelated?

Yep, the only change needed here is the addition of google-compute-engine but unfortunately the admin/update-requirements tool grabs the latest versions of all the libraries listed in the .in files.

I'm not happy with that and I'm sure that @exarkun and @moshez would frown on it, but on the other hand the updates are all minor or micro version changes, the tests all still pass and the idea behind the update-requirements tool was to keep everything up-to-date so that we can monitor our dependency versions with requires.io and respond to their warnings.....I haven't done that bit yet.

I could pin all those other requirements to their previous versions, but it doesn't seem worth it.

Merging.