The backend exposes a /status page.  If we cannot fetch the page, the
backend must have died.

This patch fixes tpo/anti-censorship/monit-configuration#2

This patch fixes #4

Louis-Philippe Véronneau generously set up this bridge for us.  David
Goulet mentions that this bridge runs in the same autonomous system (and
data centre) as his default bridge.

This patch partially fixes tpo/anti-censorship/monit-configuration#3

The bridge is now administered by Taowa Munene-Tardif and no longer by
Louis-Philippe Véronneau.

This patch partially fixes tpo/anti-censorship/monit-configuration#3

...because there's only one left.

The colocation site where the bridge is running will be shut down.

This should reduce the number of meaningless alerts that are caused by
transient issues.

This should eliminate the few false positives that we get.

GetTor doesn't set an In-Reply-To header, so we cannot verify if a reply
is in response to an email we sent earlier.  See the following ticket
for more details: <https://bugs.torproject.org/34253>

This patch uses the Date header in GetTor's email as a heuristic to
figure out if the email was in response to our request.

Now that our BridgeDB and GetTor test scripts share a mailbox, we can't
have them delete each other email messages.

This was fairly easy to add because the code is almost identical to
BridgeDB's autoresponder check.  If we want to perfectionsts, we should
outsource redundant code into a small Python library.

The script is a slightly more lightweight version of the Python script
we developed as part of <https://bugs.torproject.org/12802>.