Make Body test more isolated
Add loadpath to Ephemeris class

This class was depending on the entire gem being loaded in order
to have a proper load path to load its dependencies
Inject EphemerisRequest dependency into Ephemeris
Decouple EphemerisRequest from Client by defining SYSTEM_PROMPT
Isolate Ephemeris test and test the right things
Inject EphemerisTableParser into EphemerisParser
Isolate VectorEphemerisParserTest