[stdlib-sig] April 15th deadline to propose module removal

[Brett Cannon]

To make sure this all gets done I am putting a deadline of April 15th
for proposing module removals.

With the release schedule that Barry has drawn up, we have until June
1 to get the stdlib reorg. I don't see any big issues with meeting
this deadline, but it is something to keep in the back of everyone's
head. I think the biggest headache will be getting a 2to3 fixer to
work, but I think the fix_imports one is pretty close to being what we
need.

-Brett