Added Local Install Flag to Makefile

I added the LOCAL_INSTALL flag to the Makefile so that users who are
building on their local machines (not on the ASC computers) can build
the program without having to necessarily specify a local filepath.

If building on your local machine, you should run the following command
to build the metrosim and metrotest applications respecitvely:

make LOCAL_INSTALL=1
make tests LOCAL_INSTALL=1