Turn on verbose output for MPICH builds in Travis (#10105)

Lately many CI runs for PRs are failing due to the `mpich` build that
times out on Travis (10 mins. without output). As the timeout seems to
happen consistently during the build phase, increasing the verbosity of
that test can help working around the issue.

share/spack/qa/run-build-tests

@@ -33,8 +33,12 @@ if [ -z "$SPEC" ]; then
     exit 1
 fi
 
+if [ "${SPEC}" = "mpich" ] ; then
+    OPTIONS="-v"
+fi
+
 # Print compiler information
 spack config get compilers
 
 # Run some build smoke tests, potentially with code coverage
-${coverage_run} bin/spack install ${SPEC}
+${coverage_run} bin/spack install ${OPTIONS} ${SPEC}