Introducing pre-commit hook

• Add pre-commit hook. [Diego Hurtado]

  A pre-commit hook that runs tox has been added. This hook makes sure
  that all the tests pass before adding a commit to ensure a fully
  test-passing git history.

Introducing commit-msg hook

• Add license. [Diego Hurtado]

  The license for this project was defined as show in the LICENSE
  file.

• Add the README. [Diego Hurtado]

  The commit-msg hook is ready for use. Instructions on how to
  use were added in the README.