message: Specifying cryptography version in install docs
diff: @@ -36,7 +36,7 @@ that the required dependencies are installed: ::
  **OSX**, system python is not recommended. brew's python also ships with pip ::
  brew install pkg-config libffi openssl python
  - env LDFLAGS="-L$(brew --prefix openssl)/lib" CFLAGS="-I$(brew --prefix openssl)/include" pip install cryptography
  + env LDFLAGS="-L$(brew --prefix openssl)/lib" CFLAGS="-I$(brew --prefix openssl)/include" pip install cryptography==1.7.2
  **Windows** isn't officially supported at this point, but if you want to
  attempt it, download `get-pip.py <https://bootstrap.pypa.io/get-pip.py>`_, and run ``python get-pip.py`` which may need admin access. Then run the following: ::
  