upgrade mkdocs & mkdocs-material (#618)

Author: leibale

docs/requirements.txt

@@ -1,5 +1,5 @@
-mkdocs==1.0.4
-mkdocs-material==4.6.3
+mkdocs==1.1.2
+mkdocs-material==6.2.2
 -e git+https://github.com/RedisLabs/mkdocs-versions-menu.git#egg=mkdocs-versions-menu
 -e git+https://github.com/RedisLabs/mkdocs-include.git#egg=mkdocs-include
 -e git+https://github.com/RedisLabs/mkdocs-modules-template.git#egg=mkdocs-modules-template