ci: enable unit tests with Travis

ci: enable unit tests with Travis

When building under Travis (or another linux CI service), enable
running the fast-tests when the RUN_TESTS environment variable is set.

For the Travis service, introduce two new shared builds, since the
shared builds are the ones passing.  Builds that are statically
linked still show some issues in some of the eal_flags tests.  We make
new builds for this, rather than piggybacking, because 'at a glance'
it is difficult to determine why a build fails, and if tests were
enabled for all builds, then looking at the logs for any build would
take a significant amount of time.

Finally, the command to invoke fast tests includes a timeout
multiplier, since some CI environments don't have enough resources to
complete the tests in the default 10s timeout period.

Signed-off-by: Aaron Conole <aconole@redhat.com>
Acked-by: Michael Santana <msantana@redhat.com>
Reviewed-by: David Marchand <david.marchand@redhat.com>