DOC: Update install docs [ci skip]

[ci skip]

Author: TomAugspurger

docs/source/install.rst

@@ -1,10 +1,13 @@
 Install
 =======
 
-cyberpandas requires pandas 0.23 or newer, which is currently unreleased.
+cyberpandas requires pandas 0.23 or newer. On Python 2, the 3rd party `ipaddress`
+module is required (it's built into the standard library in Python 3).
 
-Once pandas is installed, cyberpandas can be installed from PyPI
+Once pandas is installed, cyberpandas can be installed from conda-forge::
 
-.. code-block:: none
+    conda install -c conda-forge cyberpandas
 
-   pip install cyberpandas
+Or PyPI:
+
+    pip install cyberpandas