cleanup requirements

requirements.txt

@@ -1,29 +1,3 @@
 # https://github.com/plone/buildout.coredev/blob/5.1/requirements.txt
 setuptools==33.1.1
 zc.buildout==2.9.5
-# # Sphinx / ReadTheDocs
-# alabaster==0.7.10
-# appdirs==1.4.2
-# astunparse==1.5.0
-# Babel==2.5.1
-# certifi==2017.11.5
-# chardet==3.0.4
-# docutils==0.14
-# idna==2.6
-# imagesize==0.7.1
-# Jinja2==2.10
-# MarkupSafe==1.0
-# packaging==16.8
-# Pygments==2.2.0
-# pyparsing==2.1.10
-# pytz==2017.3
-# requests==2.18.4
-# six==1.10.0
-# snowballstemmer==1.2.1
-# Sphinx==1.6.5
-# sphinx-rtd-theme==0.2.4
-# sphinxcontrib-httpdomain==1.5.0
-# sphinxcontrib-httpexample==0.7.0
-# sphinxcontrib-websupport==1.0.1
-# typing==3.6.2
-# urllib3==1.22