Update the recommended invocation of `pip` to use the `python` command,
avoiding discrepancies on systems where the `pip` and `python` commands
are not provided by the same Python installation. In the interest of
consistency, also update the configuration for the project's continuous
integration service.

Recommend additional tooling for users with more advanced needs.

Ensure that the linter's Python dependencies are satisfied in the
continuous integration environment.

Note that this is not currently necessary but only because the linter's
dependencies happen to align with those of the test generation tool. The
dependencies of the two tool should be satisfied explicitly in order to
promote isolation.

This script is intended to identify common test file formatting errors
prior to their acceptance into the project. It is designed to support
future extensions for additional validation rules.

Installing dependencies using this file increases parity between the CI
and development environment. Because the file explicitly specifies a
version of the package to be installed, this approach also produces more
predictable results overall.

Introduce configuration to allow build servers provided by the Travis CI
service to execute the test generation tool and commit the resultant
files to the canonical upstream repository.

Enabling this workflow required additional administrative work:

1. Create an account with TravisCI
2. Install the `travis` command-line utility
3. Create a "deploy key" and an encrypted version using the command
   `./make.py github_deploy_key_enc`
4. Register the deploy key with the project's GitHub account
5. Check the encrypted deploy key to the repository
6. Configure the TravisCI service to automatically build this project