Create 'pre-commit', add Python tests

* Create our 'pre-commit' hook script that runs flake8 on Python files in
  the staging area.
* Update test setup to create a git repository for testing.
* Add a test for the Python linter to confirm that it produces the
  correct output when trying to commit and that it only checks files in
  the staging index.

1 files changed, 1 insertions, 0 deletions

diff --git a/t/uncommitted.py b/t/uncommitted.py
new file mode 100644
index 0000000..0f43f2a
--- /dev/null
+++ b/t/uncommitted.py
@@ -0,0 +1 @@
+import math