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/spec/make-coverage

@@ -0,0 +1,24 @@
+#!/bin/sh
+
+set -ex
+
+rm -f .coverage_covimerage
+export PYTHON_PEP8_INDENT_TEST_PROFILE_BASE=/tmp/vim-python-pep8-profile
+
+Xvfb :99 2>/dev/null >&2 &
+export DISPLAY=:99
+
+export VIMRUNNER_REUSE_SERVER=1
+
+ret=0
+for file in ./spec/indent/*_spec.rb; do
+  # shellcheck disable=SC2086
+  bundle exec rspec "$file" $RSPEC_OPTIONS || ret=1
+
+  for p in "${PYTHON_PEP8_INDENT_TEST_PROFILE_BASE}".*; do
+    covimerage write_coverage --append "$p"
+    rm "$p"
+    covimerage report -m
+  done
+done
+exit $ret