Check to see if deps across projects can use same versions

[econchick]

Per @sigmavirus24 - the requirements files in the different projects use different versions of the same dependency, and does not take advantage of cached wheels.

[sigmavirus24]

So, I had to take care of toddlers yesterday, but I meant to make a recommendation. One of the requirements I saw was that one project requires matplotlib==1.4.2 while another requires matplotlib==1.4.3 You could more generally use matplotlib>=1.4.0,<1.5.0 here if you want to assume the 1.4.x branch should just work and not break things. This lets users take advantage of their local wheel cache.