Strive to make the spec lock file update clearer, update spec lock file

[PLeVasseur]

Example of update to remove verbosity:

    Please manually inspect FLS spec items whose checksums have changed as corresponding guidelines may need to account for these changes.
    Once resolved, you may run the following to update the local spec lock file:
    	./make.py --update-spec-lock-file

... snip ...

Error: Build errors detected in log
=== ERROR DETAILS ===
=== TRACEBACK ===
Saving traceback to build/sphinx_traceback.log
=== SPEC LOCK FILE DIFFERENCES ===
Saving spec lock file differences to to build/spec_lock_file_differences.log
Error: Process completed with exit code 1.

closes #28

[plaindocs]

This is helpful.

Can we have an entry in the readme and a link in the error message of either how to update the spec file, or ideally, how to ignore it for WIP builds?

[PLeVasseur]

Thanks @plaindocs for the suggestions. It does seem useful to mention this in the README as it's likely to happen fairly often.

Good idea on a way to silence this error if working on something. I'll give it some thought.

[PLeVasseur]

Hey @plaindocs -- I think I've addressed the ideas you brought up. Can you give it a look?

[plaindocs]

Looks great to me. 👍

[PLeVasseur]

Gonna merge this one -- thanks @plaindocs for the suggestions to improve it!