Add ndscope and gpstime portfiles
Add Portfiles for ndscope
and gpstime
to the testing port directory under the science category. Tested on macOS 10.14 18A391 and Xcode 10.0 10A255; both modules work as expected.
Also submitted merge request for gpstime
Portfile to the default MacPorts repository since it doesn't have any LIGO dependencies and might be generally useful for others.