Standardize git-pair application name

[wevtimoteo]

We were getting some warning messages complaining about application name when running tests:

You have configured application :"git-pair" in your configuration file,
but the application is not available.

This usually means one of:

  1. You have not added the application as a dependency in a mix.exs file.

  2. You are configuring an application that does not really exist.

Please ensure :"git-pair" exists or remove the configuration.

We've investigated further and discovered that we should use standardized name for application then customize escript configs.

[amadeu01]