Travis CI is not the equal of buildbot (it can't run RT kernels and
can only test building on Ubuntu with amd64) but adopting it *in
addition to* buildbot would let us do things like automatically
build-test pull requests on github without developer interference
(i.e., by pushing a temporary branch to glo)
Closes#137.
Signed-off-by: Jeff Epler <jepler@unpythonic.net>
