add credits section

this is not readable enough for non-programmers and is a little
ridiculous, but it works.

we should probably parse this from a AUTHORS file instead of going
crazy like this.

see #56

doc/credits.rst

+=========
+ Credits
+=========
+
+Those people are the ones who made Monkeysign possible.
+
+.. literalinclude:: ../monkeysign/__init__.py
+   :start-after: credits-start

doc/index.rst

@@ -16,8 +16,8 @@
    api
    ui-mockups/index
    glossary
+   credits
 
 *   :ref:`genindex`
 *   :ref:`modindex`
 *   :ref:`search`
-

monkeysign/__init__.py

@@ -48,6 +48,10 @@ __license__ = """
 
 __website__ = 'http://web.monkeysphere.info/monkeysign'
 __documentation__ = 'http://monkeysign.readthedocs.io/en/' + __version__
+# hack to include the credits in the documentation
+# maybe this should be parsed from a AUTHORS file instead, see
+# https://0xacab.org/monkeysphere/monkeysign/issues/56
+# credits-start
 __authors__ = ['In alphabetical order:',
                '',
                'Antoine Beaupré',