Remove invalid block arg from Babushka::Shell's popen3 call.
Don't queue or post run reports.
Remove Babushka::RunReporter.
Remove thread runners, which were only used for posting run reports.
Remove `babushka search`.
Clean up ~/.babushka/runs now that it's no longer used.
Add ruby-2.0.0 to the list of travis rubies.
Don't report bugs post-run.
Remove Babushka::BugReporter.
Remove Babushka::Task#reportable, which isn't used anymore.
Merge branch 'remove-run-reporter' -- a worthwhile experiment, but...

The reports turned out not to be very useful, mainly because the most
substantial and interesting deps people run are either private, or not knowably
public at runtime (e.g. in a public source, but cloned from a read+write ssh
remote). This meant that the data collected was only a thin slice of the total
usage.

Secondly, having a community database makes it easy to find and run deps
without checking what they do. This wasn't my intention, and I don't know of
anyone actually doing this, but I don't think it's wise to help this behaviour.
I still want running others' deps to be easy (i.e. `babushka source:dep`), but
listing deps in the community DB might be mistaken for an endorsement.
Merge branch 'remove-bug-reporter' -- doesn't give us much over manual bug reports.

The bug reporter was only reporting a narrow set of bugs, i.e. exceptions hit
during dep definition. The intention was to report bugs in babushka core, but
the way it was being triggered meant it reported problems defining any dep, not
just core ones, and excluded exceptions occurring in babushka itself.

Secondly, this class was a UI problem, because failed runs during dep
definition would block at a confirmation prompt instead of exiting straight to
the command prompt. This is unexpected behaviour and would only be justified by
a big enough win elsewhere.

Thirdly, the reporter just wasn't used much. I hardly ever got bug reporter
emails, which means either it's almost never triggered, or users don't send
the reports through when it is. Either way, it's not doing anything useful, so
it's time to prune it.
v0.16.4 - Remove reporting of dep runs and bugs, neither of which were very useful. See the corresponding merge commits for discussion.