Setting up various badges for the repository

[cmacmackin]

This commit will add badges for CI status, code coverage, etc. to the repository README. It will also update the CI system a bit. It is still a work-in-progress.

[makeclean]

This is all good stuff, but we should be moving stuff to use INL's CI system CIVET which is much more integrated with MOOSE development and when developemen tis further along will be ran by INL to make sure they don' t break app

[cmacmackin]

That should probably be added to the "Backlog" column for the project.

[codecov]

Welcome to Codecov 🎉

Once you merge this PR into your default branch, you're all set! Codecov will compare coverage reports and display results in all future pull requests.

ℹ️ You can also turn on project coverage checks and project coverage reporting on Pull Request comment

Thanks for integrating Codecov - We've got you covered ☂️

[cmacmackin]

In the task for this PR it says to include badges for "Dependency (for MFEM)". What is meant by this? The version we depend on? At present I think we're still depending on a particular commit of a fork, so that doesn't really apply.

[cmacmackin]

I've added all of the badges I can think of at the moment. I often like to put in a badge for the status of building/deploying documentation, but we can think about that once some has been written.

[alexanderianblair]

Thanks Chris - this looks good, and should help with reporting code quality of new commits going forward.

Happy for this to go in as-is; minor comment to trim the cclake build script is optional and could be implemented in a later PR.