Add service checks to CI test

[ryangoree]

This adds basic checks to ensure the following:

• The .env file is created properly
• Services expected to run then exit (mine, fund-accounts) do so with a zero exit code
• Services expected to still be running are running

If any changes to the /services directory were made, the images will be rebuilt with a new tag and used in the checks.

[slundqui]

This is great, thanks!