Add hooks for running linters and tests

Add the `scripts/setup-hooks.sh` script which sets the following hooks
up:
- The `post-commit` hook runs the linter after every `git commit`,
  letting you know if there are code style or rule linter offenses you
  need to fix.
- The `pre-push` hook runs the linter and the tests and block the `git
  push` if they do not succeed.
  This way you realise if everything is alright without the need of
  sending a PR.

scripts/setup-hooks.sh

@@ -0,0 +1,25 @@
+#!/bin/sh
+
+GIT_DIR=`git rev-parse --show-toplevel`
+cd $GIT_DIR
+
+# hooks may exist already (e.g. git-lfs configuration)
+# If the `.git/hooks/$arg` file doesn't exist it, initialize with `#!/bin/sh`
+# After that append `scripts/hooks/$arg` and ensure they can be run
+create_hook() {
+  if [[ ! -e .git/hooks/$1 ]]; then
+    echo '#!/bin/sh' > .git/hooks/$1
+  fi
+  cat scripts/hooks/$1 >> .git/hooks/$1
+  chmod +x .git/hooks/$1
+}
+
+echo '\n#### Copying hooks into .git/hooks'
+create_hook 'post-commit'
+create_hook 'pre-push'
+
+echo '\n#### Installing linter/test dependencies\n'
+pip install pycodestyle
+pytest-sugar
+pip install https://github.com/williballenthin/vivisect/zipball/master
+python setup.py develop