Try to fix .gitpod.Dockerfile, add new dependencies

Author: jnareb

.gitpod.Dockerfile

@@ -5,10 +5,16 @@ FROM gitpod/workspace-full
 # RUN brew install bastet
 #
 # More information: https://www.gitpod.io/docs/config-docker/
+RUN pip install --upgrade pip
 RUN pip install nbdev
 RUN pip install networkx
 RUN pip install matplotlib
+RUN pip install seaborn
+RUN pip install pandas
+RUN pip install tables
+CD /workspace/git-commit-graph-ext
 RUN nbdev_install_git_hooks
 # Jekyll for GitHub Pages
+RUN sudo apt-get install ruby-full build-essential zlib1g-dev
 RUN gem install jekyll bundler
-RUN cd docs && bundle install
+RUN cd docs && bundle install