Integrate koji scratch builds.

Here's some example output from a run::

```
[2014-10-15 13:50:17][    fedmsg    INFO] Handling anitya msg u'2014-cbc30c4d-0aba-4526-b4f1-80daef452821'
[2014-10-15 13:50:17][    fedmsg    INFO] Running '/usr/bin/repoquery --quiet --archlist=src --all --qf %{name}\t%{version}\t%{release}'
[2014-10-15 13:50:19][    fedmsg    INFO] Comparing upstream 20101124 against repo 1.8-4.fc20
[2014-10-15 13:50:19][    fedmsg    INFO] OK, 20101124 is newer than 1.8-4.fc20
[2014-10-15 13:50:20][    fedmsg    INFO] Found and updating bug 'https://partner-bugzilla.redhat.com/show_bug.cgi?id=1143040'
[2014-10-15 13:50:20][    fedmsg    INFO] Comparing '', u'20101124'
[2014-10-15 13:50:21][    fedmsg    INFO] Updated bug: https://partner-bugzilla.redhat.com/show_bug.cgi?id=1143040
[2014-10-15 13:50:21][    fedmsg    INFO] Now with RHBZ <Bug #1143040 on https://partner-bugzilla.redhat.com/xmlrpc.cgi at 0x39d0450>, time to do koji stuff
[2014-10-15 13:50:21][    fedmsg    INFO] Cloning 'http://pkgs.fedoraproject.org/cgit/adf-accanthis-fonts.git' to '/var/tmp/thn-JFsBDd'
[2014-10-15 13:50:30][    fedmsg    INFO] Running u'/usr/bin/rpmdev-bumpspec --new 20101124 -c "Latest upstream, 20101124 for ##1143040 NEW        - nicolas.mailhot@laposte.net - testing anitya stuff" -u "Fedora Release Monitoring <release-monitoring@fedoraproject.org>" /var/tmp/thn-JFsBDd/adf-accanthis-fonts.spec' in None
[2014-10-15 13:50:30][    fedmsg    INFO] Running u'spectool -g /var/tmp/thn-JFsBDd/adf-accanthis-fonts.spec' in '/var/tmp/thn-JFsBDd'
[2014-10-15 13:50:33][    fedmsg    INFO] Running 'fedpkg srpm' in '/var/tmp/thn-JFsBDd'
[2014-10-15 13:50:36][    fedmsg    INFO] Uploading /var/tmp/thn-JFsBDd/adf-accanthis-fonts-20101124-1.fc22.src.rpm to koji
[2014-10-15 13:50:43][    fedmsg    INFO] Intiating koji build for {'source': 'cli-build/1413395436.23029.FDAMthWQ/adf-accanthis-fonts-20101124-1.fc22.src.rpm', 'target': 'rawhide', 'opts': {'scratch': True}, 'name': u'adf-accanthis-fonts'}
[2014-10-15 13:50:43][    fedmsg    INFO] Done: task_id=7876402
[2014-10-15 13:50:44][    fedmsg    INFO] Handling koji msg u'2014-88f96b99-d9b1-404b-9de8-58e57ea951ea'
[2014-10-15 13:50:44][    fedmsg    INFO] Heard word that our task 7876402 is u'OPEN'.
[2014-10-15 13:56:17][    fedmsg    INFO] Handling koji msg u'2014-f5f01771-a67e-4f81-8a2a-570ed1e5ea95'
[2014-10-15 13:56:17][    fedmsg    INFO] Heard word that our task 7876402 is u'CLOSED'.
[2014-10-15 13:56:18][    fedmsg    INFO] Followed up on bug: https://partner-bugzilla.redhat.com/show_bug.cgi?id=1143040
```
> I wonder if fedpkg srpm will not pull all the patches & co from the git, so maybe we can avoid the call to spectool.

I don't think it will work.  AFAIK, `fedpkg srpm` downloads the current source from the lookaside cache (the *old* tarball), while `spectool -g` will download the new source from upstream.