1. Unbreak the deployment script (hopefully the last time).
2. No longer attempt to upload docs when building from non-main repos.

Fixes #3592.

Signed-off-by: Edward Z. Yang <ezyang@cs.stanford.edu>

Lots of changes:

    - When possible, we use the container infrastructure (sudo: false)
      rather than Google Compute Engine infrastructure (sudo: required).
      Unfortunately, we can't use GCE for the Linux builds, where
      reduced RAM available hoses are GHC build.

    - Switched from using ./Setup and old-style cabal to new-build.
      There are numerous great benefits but the best is that
      .cabal/store can be cached on Travis, leading to huge speedups
      on the build.  Downside is we need to string-and-ceiling-wax
      support for test/haddock/etc.

    - I stopped bootstrapping on every build we do; instead there
      is a separate bootstrap build we do to make sure that that
      is working.  This also speeds up the basic builds since
      we are not building Cabal/cabal-install multiple times.

    - There are some hacks.  The big one is setting CABAL_BUILDDIR
      explicitly; this smooths over quite a few infelicities in
      the current new-build implementation.

Signed-off-by: Edward Z. Yang <ezyang@cs.stanford.edu>

Signed-off-by: Edward Z. Yang <ezyang@cs.stanford.edu>

[ci skip]

Fixes #3543.

Now that we bootstrap Cabal and cabal-install, we don't have to install
the package anymore.

It makes the build fail due to timeout.

/cc @ezyang

Signed-off-by: Edward Z. Yang <ezyang@cs.stanford.edu>

Signed-off-by: Edward Z. Yang <ezyang@cs.stanford.edu>

Disable fast finish as it is buggy w.r.t. notifications https://github.com/travis-ci/travis-ci/issues/4928

 [ci skip]

Signed-off-by: Edward Z. Yang <ezyang@cs.stanford.edu>

Signed-off-by: Edward Z. Yang <ezyang@cs.stanford.edu>

Signed-off-by: Edward Z. Yang <ezyang@cs.stanford.edu>

Signed-off-by: Edward Z. Yang <ezyang@cs.stanford.edu>

Signed-off-by: Edward Z. Yang <ezyang@cs.stanford.edu>

In the process, I refactored the test suite a bit to be more robust
and handle the --with-compiler more correctly in most cases.

One note: I turned off the HPC tests with the GHC and WITH_GHC
parameters don't match.  In principle this should work but there
is some sort of bug.  I don't plan on fixing the bug.

Signed-off-by: Edward Z. Yang <ezyang@cs.stanford.edu>

Signed-off-by: Edward Z. Yang <ezyang@cs.stanford.edu>

See https://github.com/well-typed/hackage-security/pull/151.

hackage-security doesn't know about Cabal 1.25.