Add intensity control for RGB led
Merge pull request #57 from mattande/rgb_intensity_base

Add intensity control for RGB led
Update build products after merging PR
Vary error return values in tinker to help with debugging

See
https://community.sparkdevices.com/t/unable-to-talk-to-tinker-firmware-w-python-via-rest/2072/9
Latest build after updating hardware driver files in core-common-lib
#undef SPARK_WLAN_ENABLE in main.h to disable WLAN and execute loop()
Fixed merge conflict issue with latest master and updated binaries