As a result, our own .travis.yml can focus on testing
install-racket.sh as of the current commit.
(I am still using test.sh and `for` loops. It's not immediately
obvious to me how to express that instead using a Travis job matrix --
or that doing so would be any clearer.)
Namely, added test.sh to run through all the possible downloads and test for validity.
Added handler for TEST=1 in install-racket.sh.
Normalize urls as much as possible and to get minimal installs working
properly. This can probably be merged to master and drop the minimal
branch entirely.
I think there is still some cleanup that can happen. The various linux
flavors can probably be unified, if not parameterized.
This patch removes SCOPE_SNAPSHOT, as it seems to point to incredibly
stale content. RELEASE does too, but there is a note that it is only
valid during release phases.
