Add 'tests.bish' to run all tests.
Add 'tests.bish' to run all tests.

Note that BISH_ROOT will have to be set correctly in order for this
script to work. It needs to know the path to the bish executable (and
stdlib) in order to compile and run all the tests.

tdenniston/bish,AICIDNN/bish,lw7360/bish,lw7360/bish,AOSC-Dev/bish,tdenniston/bish,AOSC-Dev/bish,AICIDNN/bish