[V3] Pin discord.py for beta 16 release (#1848)

* Update main requirements

* Update docs requirements

* Black reformat after version update

* Pin dpy  in docs

docs/requirements.txt

@@ -1,30 +1,37 @@
 -i https://pypi.org/simple
 alabaster==0.7.10
+appdirs==1.4.3
+atomicwrites==1.1.5
 attrs==18.1.0
-babel==2.5.3
+babel==2.6.0
+black==18.6b2
 certifi==2018.4.16
 chardet==3.0.4
+click==6.7
 docutils==0.14
 idna==2.6
 imagesize==1.0.0
 jinja2==2.10
 markupsafe==1.0
-more-itertools==4.1.0
+more-itertools==4.2.0
 packaging==17.1
 pluggy==0.6.0
 py==1.5.3
 pygments==2.2.0
 pyparsing==2.2.0
 pytest-asyncio==0.8.0
-pytest==3.5.1
+pytest==3.6.1
 pytz==2018.4
 requests==2.18.4
 six==1.11.0
 snowballstemmer==1.2.1
-sphinx-rtd-theme==0.3.1
-sphinx==1.7.4
+sphinx-rtd-theme==0.4.0
+sphinx==1.7.5
 sphinxcontrib-asyncio==0.2.0
-sphinxcontrib-websupport==1.0.1
+sphinxcontrib-websupport==1.1.0
+toml==0.9.4
+tox==3.0.0
 urllib3==1.22
+virtualenv==16.0.0
 yarl==0.18.0
-git+https://github.com/Rapptz/discord.py@rewrite#egg=discord.py-1.0
+git+https://github.com/Rapptz/discord.py@7eb918b19e3e60b56eb9039eb267f8f3477c5e17#egg=discord.py-1.0