update installation docs to use pip now that package is uploaded to pypi

docs/installation.rst

@@ -9,10 +9,18 @@ You will need the following to use ``lmodule``.
 - Python 3.6 or higher
 - Lmod 7 or higher
 
-Setup
+
+PyPI Installation
+--------------------
+
+You can install lmdoule via pip as follows::
+
+    pip install lmodule
+
+Git
 -------
 
-If you have not done so, clone the repository as follows::
+If you prefer to use the latest codebase you can clone the repository as follows::
 
     $ git clone https://github.com/HPC-buildtest/lmodule.git
 
@@ -25,3 +33,13 @@ Next you will want to install lmodule in your python environment::
     $ python3 setup.py install
 
 
+Validation
+-----------
+
+If you are able to install lmodule in your python environment, you can test it as follows::
+
+
+    $ python -c "from lmod.module import Module; print(Module().version())"
+    7.8.16
+
+The above command will import the Module class and return the Lmod version in your system.