Remove mkdocs-material from requirements.txt (#109)

* remove mkdocs-material from requirements.txt as it is only used to generate the documentation site of this plugin, not as actual code dependency

* syntaxx

* stack overflow brainz

__tests__/setup-pip.sh

@@ -1,4 +1,5 @@
 #!/bin/bash
 
 python -m pip install --upgrade pip
-pip install -r requirements.txt
+pip install -r requirements.txt
+pip install mkdocs-material==9.2.3

requirements.txt

@@ -1,6 +1,6 @@
 flake8>=3.7.8
 mkdocs>=1.2.3
-mkdocs-material>=5.1.0
 mkdocs-git-authors-plugin==0.3.2
 mkdocs-git-revision-date-localized-plugin==0.5.0
 python-slugify==4.0.1
+importlib-metadata==4.13.0