First commit for GPS code, Using HardwareSerial for Serial comms.

_rodGPS_SimpleDistance() function to calculate distance between two points.
_rodGPS_MakeReading() to make a reading from GPS IC.
_rodGPS_PrintGPRMC() to print data
simple_GPRMC struct defined to store data given by IC. Use std::atof to convert the strings to float values

Signed-off-by: Rodrigo Amaral <roaa1g19@soton.ac.uk>