Bump babel from 2.2.0 to 2.9.1

requirements-docs.txt

@@ -4,16 +4,33 @@
 #
 #    pip-compile --no-index requirements-docs.in
 #
-alabaster==0.7.7          # via sphinx
-babel==2.2.0              # via sphinx
-docutils==0.12            # via sphinx
-jinja2==2.8               # via sphinx
-markupsafe==0.23          # via jinja2
-pygments==2.1.2           # via sphinx
-pytz==2015.7              # via babel
-six==1.10.0               # via sphinx
-snowballstemmer==1.2.1    # via sphinx
-sphinx-rtd-theme==0.1.9
+alabaster==0.7.7
+    # via sphinx
+babel==2.9.1
+    # via sphinx
+docutils==0.12
+    # via sphinx
+jinja2==2.8
+    # via sphinx
+markupsafe==0.23
+    # via jinja2
+pygments==2.1.2
+    # via sphinx
+pytz==2015.7
+    # via babel
+six==1.10.0
+    # via sphinx
+snowballstemmer==1.2.1
+    # via sphinx
 sphinx==1.3.6
+    # via
+    #   -r requirements-docs.in
+    #   sphinx-rtd-theme
+sphinx-rtd-theme==0.1.9
+    # via
+    #   -r requirements-docs.in
+    #   sphinx
 thrift==0.9.2
+    # via -r requirements-docs.in
 wrapt==1.10.8
+    # via -r requirements-docs.in