Upgrade PEX to 1.2.2

[dsully]

No description provided.

[lorencarvalho]

tests failing on:

Could not find compatible interpreter

This error is from pex itself, here's the block that raises it: https://github.com/pantsbuild/pex/blob/7e8faa2cd32ade42f6a4306828d44765c4f2a655/pex/bin/pex.py#L463-L494

Since we don't pass a --python arg, this line resolves the interpreter path:

interpreter = PythonInterpreter.get()

Which grabs the interpreter from sys.executable:

  @classmethod
  def get(cls):
    return cls.from_binary(sys.executable)

Really not sure why this would be failing in such a way...

[ethankhall]

I don't think this needs to be updated with the repo.

[dsully]

It can't hurt though.

[zvezdan]

Did you check if setuptools>=19.1.1 actually works with the packages and products we build internally?
I did and I can confirm it doesn't.
Why is this update needed right now?

[dsully]

@zvezdan - there's an incompatibility between the new version of CacheControl and pex (which also uses CacheControl).

pex-tool/pex#357

[zvezdan]

@dsully We upgraded pex, setuptools, and more in the #145 and to higher versions than this PR.
Can we close/discard this?