Centos7 build fails

Seems like a slightly different issue from #510

boxcutter/centos73

I am new to this process so please let me know what other information you need. I appreciate any assistance.

```
----------
ID: cp-artifacts-up calamari/repobuild/calamari-repo-*.tar.gz
Function: cmd.run
Name: cp calamari/repobuild/calamari-repo-*.tar.gz /git
Result: False
Comment: Command "cp calamari/repobuild/calamari-repo-*.tar.gz /git" run
Started: 18:51:58.937658
Duration: 7.167 ms
Changes:
----------
pid:
28779
retcode:
1
stderr:
cp: cannot stat 'calamari/repobuild/calamari-repo-*.tar.gz': No such file or directory
stdout:
----------
ID: cp-artifacts-up rpmbuild/RPMS/*/calamari-server-*.rpm
Function: cmd.run
Name: cp rpmbuild/RPMS/*/calamari-server-*.rpm /git
Result: True
Comment: Command "cp rpmbuild/RPMS/*/calamari-server-*.rpm /git" run
Started: 18:51:58.944982
Duration: 90.204 ms
Changes:
----------
pid:
28780
retcode:
0
stderr:
stdout:
----------
ID: cp-artifacts-up Diamond/dist/diamond-*.rpm
Function: cmd.run
Name: cp Diamond/dist/diamond-*.rpm /git
Result: False
Comment: Command "cp Diamond/dist/diamond-*.rpm /git" run
Started: 18:51:59.035398
Duration: 8.102 ms
Changes:
----------
pid:
28781
retcode:
1
stderr:
cp: cannot stat 'Diamond/dist/diamond-*.rpm': No such file or directory
stdout:

```

Start with the boxcutter/centos73 build and the logged artifact-copy commands. Trace the earlier build steps that should create calamari/repobuild/calamari-repo-*.tar.gz and Diamond/dist/diamond-*.rpm, then rerun the build to confirm those artifacts exist and all copy steps succeed.

Written by the indexing model from the issue text.