Upgrade gcloud dependency to google-cloud 0.19.x

[bjwatson]

Fixes #103 and #102.

[bjwatson]

Apparently #100 was not as low-risk as I thought. Getting review on this one, but we should it quickly since I broke master.

Never mind. This is more involved than I thought. I reverted the offending change from master, so the urgency is somewhat reduced.

There's still a version conflict in the self-service instructions that originally motivated what I was doing here.

[shinfan]

Travis seems cannot import "google.cloud". Is this module name incorrect?

[geigerj]

@shinfan what's especially strange is that the import error only happens in the pylint environment, not pep8 or py27...

[geigerj]

@shinfan From the Travis log:

pylint-errors installed:...
...google-cloud==0.19.0...

So google-cloud should be installed available in the pylint-errors environment. And

$ virtualenv venv
$ . venv/bin/activate
(venv) $ pip install google-cloud==0.19.0
  ...
(venv) $ python
Python 2.7.12 (default, Aug 24 2016, 08:19:55) 
[GCC 4.8.4] on linux2
Type "help", "copyright", "credits" or "license" for more information.
>>> import google.cloud
>>>

So the module google.cloud name seems OK.

[shinfan]

Umm this is strange...Can you reproduce the issue locally?

[lukesneeringer]

This is way out of date at this point. Declaring it dead.