I just ported and published the Adafruit_HDC1000 library for Photon. This is a library for the TI HDC1008 Humidity + Temp sensor. I corrected and added some features.
Designed specifically to work with the HDC1008 breakout in the Adafruit shop: https://www.adafruit.com/products/2635
Sensor datasheet: http://www.ti.com/lit/ds/symlink/hdc1008.pdf