Update MP UT to support arbitrary # of GPUs; multiple bugfixes (#16)

* Fixing temp file creation/deletion for Clique kernel mode.

* Refactoring of MP unit tests; include bugfixes and general support for any number of GPUs

* GroupCall MP UT properly quits when too many devices specified

* MP UT will programmatically set NCCL_COMM_ID if not specified; updated install script

install.sh

@@ -200,10 +200,10 @@ if ($run_tests); then
     if (test -f "./test/UnitTests"); then
         if ($run_tests_all); then
             ./test/UnitTests
-            NCCL_COMM_ID=$HOSTNAME:55512 ./test/UnitTestsMultiProcess
+            ./test/UnitTestsMultiProcess
         else
             ./test/UnitTests --gtest_filter="BroadcastCorrectnessSweep*:*float32*"
-            NCCL_COMM_ID=$HOSTNAME:55512 ./test/UnitTestsMultiProcess --gtest_filter="BroadcastMultiProcessCorrectnessSweep*:*float32*"
+            ./test/UnitTestsMultiProcess --gtest_filter="BroadcastMultiProcessCorrectnessSweep*:*float32*"
         fi
     else
         echo "Unit tests have not been built yet; please re-run script with -t to build unit tests."