fix(client): update PyInstaller to package requests lib properly

The versions of the `deis` CLI created by `make -C client/ build` were using [PyInstaller 2.1](https://github.com/pyinstaller/pyinstaller/releases/tag/v2.1), the current release. This updates PyInstaller used for packaging to [a current SHA](https://github.com/pyinstaller/pyinstaller/commits/7413317176ac5d2b1196f7d7855b796328dd9609) in their development branch, which includes [a hook script](https://github.com/pyinstaller/pyinstaller/blob/develop/PyInstaller/hooks/hook-requests.py) for the python requests library to bundle its data files correctly.

Fixes #2719.