Added pgmspace.h
Added pgmspace.h
Updated function name to match enableAutoRange in Adafruit_Sensor
Added timestamp values
Merge branch 'master' of https://github.com/adafruit/Adafruit_TSL2561

# By Kevin Townsend
# Via Kevin Townsend
* 'master' of https://github.com/adafruit/Adafruit_TSL2561:
  Added timestamp values
  Updated function name to match enableAutoRange in Adafruit_Sensor
  Added pgmspace.h
  Added pgmspace.h