[Halld-offline] [EXTERNAL] Automated Pull Request Tests are now working again

[Sean Dobbs]

Hi all,

Following up on Tuesday's software meeting, where it was reported that
the automated acceptance tests that are run after the build test were
not working (and had not been for quite awhile), I went through and
fixed several problems with the current system.  It should be working
again.

>From the build_scripts pull request:
There were several issues:

- Testing code was still assuming "sim-recon" repository
- The tests relied on an EVIO file sitting on cache which fell off -
moved this back to /work/halld/pull_request_test
- The logic for building the GitHub comment was wrong - fixed and
added more descriptive comments


This should provide a useful framework for adding more tests and to
build tools to make more quantitative comparisons, which would be an
interesting project for someone, as we discussed.

Cheers,
Sean