Update README.md

change the repo url
modify sensor type for API v1.3
regulate the fields to be modified in Constants.java
make changes to constants.java
change NEW_GET_DEVICE_TYPES
change Attributes, Getters, Setters for DeciceType in API 1.3
change all() for DeviceType in API 1.3
make changes to scala files
Merge branch 'master' of github.com:cmusv-sc/ArchF2013-Project3-FT
change scala code for DeviceType for API 1.3
complete the sensors
Merge branch 'master' of https://github.com/cmusv-sc/ArchF2013-Project3-FT
finish the device
Update to SensorCategory from API 1.3
Merged SensorCategory.java
Merge branch 'master' of https://github.com/cmusv-sc/ArchF2013-Project3-FT
Complete the GET DeviceTypes for API 1.3
Complete the GET DeviceTypes for API 1.3
Merge branch 'master' of https://github.com/cmusv-sc/ArchF2013-Project3-FT
fix the nullpointer if we have empty result from API
Adding code for Adding new SensorCategory