- Replace dashes with underscores in shell function names, sh doesn't support dashes in function names (not happy about the inconsistency, but it'll do for now).

- Updated list of shell script to check with pre-comit.
- Renamed train-wifi.sh to train-wifi .

- Added update-requirements Git alias (same as the update-requirements shell alias but also commits the changed files.)

simpler shell alias to just update the requirements files without any
Git.

- Added autosquash Git alias.

- Reverted OSX TravisCi test since the only test is using pre-commit now.

- Added test to install script, test also on OSX for a BSD userland.

- The version of shellcheck is TravisCI is older and ignores the disable
decleration, use xargs instead shell command substition.

- Revert change brought on from running shellcheck, breaks scripts.
Instead explictly turn off said check.

- Check for repo before running update-requirements.

- Added git hooks directory and installation instructions to README, for now just regenerate the SSH config after merge (and therefore pull).