docs: Remove hint regarding Cython

It is obsolete by now and there is no need to use it anymore.

docs/contributing/testing/unit-and-functional.rst

@@ -1,61 +1,58 b''
 
 .. _test-unit-and-functional:
 
 ===========================
  Unit and Functional Tests
 ===========================
 
 
 
 py.test based test suite
 ========================
 
 
 The test suite is in the folder :file:`rhodecode/tests/` and should be run with
 the test runner `py.test` inside of your `nix-shell` environment::
 
-   # In case you need the cythonized version
-   CYTHONIZE=1 python setup.py develop --prefix=$tmp_path
-
    py.test rhodecode
 
 
 
 py.test integration
 -------------------
 
 The integration with the test runner is based on the following three parts:
 
 - `pytest_pylons` is a py.test plugin which does the integration with the
   Pylons web framework. It sets up the Pylons environment based on the given ini
   file.
 
   Tests which depend on the Pylons environment to be set up must request the
   fixture `pylonsapp`.
 
 - :file:`rhodecode/tests/plugin.py` contains the integration of py.test with
   RhodeCode Enterprise itself.
 
 - :file:`conftest.py` plugins are used to provide a special integration for
   certain groups of tests based on the directory location.
 
 
 
 VCS backend selection
 ---------------------
 
 The py.test integration provides a parameter `--backends`. It will skip all
 tests which are marked for other backends.
 
 To run only Subversion tests::
 
    py.test rhodecode --backends=svn
 
 
 
 Frontend / Styling support
 ==========================
 
 All relevant style components have an example inside of the "Style" section
 within the application. Enable the setting `debug_style` to make this section
 visible in your local instance of the application.