build: Have travis-ci run integration tests in parallel.

This partially reverts 24fb1306e0204c931bb0cab63d04c6534d49bb78 now that
we have a fix for the race condition identified. We keep the additional
`check-programs` target around for convenience.

Signed-off-by: Philip Tricca <philip.b.tricca@intel.com>
diff --git a/.travis.yml b/.travis.yml
index da104df..4557c57 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -68,8 +68,7 @@
     fi
   - ../configure --enable-unit $CONFIGURE_OPTIONS --with-simulatorbin=$(pwd)/../ibmtpm/src/tpm_server
   - make -j$(nproc) distcheck
-  - make -j$(nproc) check-programs
-  - make -j1 check
+  - make -j$(nproc) check
   - cat test-suite.log
   - |
     for LOG in $(ls -1 test/unit/*.log); do