nod to alchemtest

- added to credits
- added in sidebar (it contains datasets for alchemical free
  energy calculations)

Author: orbeckst

docs/conf.py

@@ -122,7 +122,8 @@
     'github_button': False,
     'github_banner': True,
     'extra_nav_links': {
-        "MDAnalysis": "https://www.mdanalysis.org",
+        "MDAnalysis": "https://www.mdanalysis.org/",
+        "alchemtest": "https://alchemtest.readthedocs.io/",
     },
     'show_related': True,
     'fixed_sidebar': False,

docs/credits.rst

@@ -7,7 +7,8 @@
 The **MDAnalysisData** package is modelled after `sklearn.datasets
 <http://scikit-learn.org/stable/modules/classes.html#module-sklearn.datasets>`_
 and uses some of its code (under the `BSD 3-clause license
-<https://github.com/scikit-learn/scikit-learn/blob/master/COPYING>`_).
+<https://github.com/scikit-learn/scikit-learn/blob/master/COPYING>`_)
+and alchemtest_.
 
 No data are included in this package; please see the `DESCR` attribute
 for each data set for authorship, citation, and license information
@@ -18,3 +19,5 @@ License v3.0`_ (or any later version).
 
 .. _`GNU General Public License v3.0`:
    https://www.gnu.org/licenses/gpl-3.0.en.html
+
+.. _alchemtest: https://alchemtest.readthedocs.io