Adds support to make check

The regression and unit tests are now integrated with `make check`.
It is possible to use make check -jN to have multiple tests running
in parallel.

test/test-suite.sh

@@ -0,0 +1,11 @@
+#!/bin/bash
+
+TEST=$1 1> /dev/null
+cd test 1> /dev/null
+if [[ $TEST == *"test-cases/regression/"* ]]
+then
+      ./regression_tests ../$*
+else
+      ./unit_tests ../$*
+fi
+cd - 1> /dev/null