Fixed https://github.com/amix/vimrc/issues/546

This is done by removing custom FileType indent options, and using
`vim-python-pep8-indent` plugin.

sources_non_forked/vim-python-pep8-indent/Dockerfile

@@ -0,0 +1,24 @@
+FROM testbed/vim:latest
+
+RUN apk --no-cache add gtk+2.0-dev libx11-dev libxt-dev mcookie xauth xvfb
+# NOTE: +profile needs huge features.
+RUN install_vim -tag v8.1.0129 -name vim --with-features=huge \
+  --disable-channel --disable-netbeans --disable-xim \
+  --enable-gui=gtk2 --with-x -build
+RUN ln -s /vim-build/bin/vim /usr/bin/gvim
+RUN gvim --version
+
+# Install covimerage and vint.
+# NOTE: we have py2 already via gtk+2.0-dev.
+# NOTE: enum34+pathlib+typing gets installed as workaround for broken vim-vint wheel.
+RUN apk --no-cache add py2-pip \
+  && pip install --no-cache-dir codecov covimerage==0.0.9 vim-vint enum34 pathlib typing \
+  && rm -rf /usr/include /usr/lib/python*/turtle* /usr/lib/python*/tkinter
+
+WORKDIR /vim-python-pep8-indent
+
+ADD Gemfile .
+RUN apk --no-cache add coreutils ruby-bundler
+RUN bundle install
+
+ENTRYPOINT ["rspec", "spec"]