Fixes CVE-2019-10906 by further simplifies the requirements.txt.

requirements.txt

@@ -1,56 +1,2 @@
-alabaster==0.7.10
-appnope==0.1.0
-backports-abc==0.5
-backports.shutil-get-terminal-size==1.0.0
-bleach==2.0.0
-certifi==2017.7.27.1
-chardet==3.0.4
-configparser==3.5.0
-decorator==4.0.11
-docutils==0.14
-entrypoints==0.2.3
-enum34==1.1.6
-functools32==3.2.3.post2
-html5lib==0.999999999
-idna==2.5
-imagesize==0.7.1
-Jinja2==2.9.6
-jsonschema==2.6.0
-MarkupSafe==1.0
-mistune>=0.8.1
-nbconvert==5.2.1
-nbformat==4.3.0
-pandocfilters==1.4.1
-pathlib2==2.3.0
-pexpect==4.2.1
-pickleshare==0.7.4
-pkginfo==1.4.1
-powerline-status==2.6
-prompt-toolkit==1.0.14
-ptyprocess==0.5.2
-Pygments==2.2.0
-python-dateutil==2.6.1
-pytz==2017.2
-pyzmq==16.0.2
-qtconsole==4.3.0
-requests==2.20.0
-requests-toolbelt==0.8.0
-scandir==1.5
-simplegeneric==0.8.1
-singledispatch==3.4.0.3
-six==1.10.0
-snowballstemmer==1.2.1
-Sphinx==1.6.5
-sphinxcontrib-websupport==1.0.1
-telepot==12.2
-terminado==0.6
-testpath==0.3.1
-tornado==4.5.1
-tqdm==4.15.0
-traitlets==4.3.2
-twine==1.9.1
-typing==3.6.2
-urllib3>=1.23
-wcwidth==0.1.7
-webencodings==0.5.1
-widgetsnbextension==2.0.0
+recommonmark==0.5.0
+sphinx_rtd_theme==0.4.3