upgrade mkdocs version

mkdocs==1.1.2

Pygments==2.6.1

markdown==3.2.2

pymdown-extensions==7.1

mkdocs-material-extensions==1.0

Pygments==2.7.1

markdown==3.3.1

pymdown-extensions==8.0.1

mkdocs-material==6.0.2

mkdocs-material-extensions==1.0.1

mkdocs-minify-plugin==0.3.0

mkdocs-git-revision-date-localized-plugin==0.5.2

mkdocs-awesome-pages-plugin==2.2.1

requests==2.22.0

mkdocs-git-revision-date-localized-plugin==0.7.2

mkdocs-awesome-pages-plugin==2.4.0

requests==2.24.0