Update installation.rst

docs/installation.rst

@@ -4,25 +4,6 @@
 Installation
 ============
 
-
-Stable release
---------------
-
-To install data2passcal, run this command in your terminal:
-
-.. code-block:: console
-
-    $ pip install data2passcal
-
-This is the preferred method to install data2passcal, as it will always install the most recent stable release.
-
-If you don't have `pip`_ installed, this `Python installation guide`_ can guide
-you through the process.
-
-.. _pip: https://pip.pypa.io
-.. _Python installation guide: http://docs.python-guide.org/en/latest/starting/installation/
-
-
 From sources
 ------------