Revert "ci: Disable travis test until they can be fixed"

This reverts commit ed75dfdec4e0dc93d65191fabfceddf33b66da3f.

Signed-off-by: Sherry Zhang <sherry.zhang2@arm.com>
Change-Id: I4ff5e2ac9555d03d5b13d4a9bd687247440dbc81
diff --git a/.travis.yml-disabled b/.travis.yml
similarity index 100%
rename from .travis.yml-disabled
rename to .travis.yml