Create MPU9250BasicAHRS_t3.ino

This is the same sketch  but uses the i2c_t3.h 'Wire' library specifically designed for Teensy 3.1. It allows easy access to Teensy specific  capabilities such as specification of which set of hardware i2c pins will be used, the bus speed (up to 1 MHz!) and also allows master and/or slave designation to handle multiplexing between i2c devices. See www.pjrc.com/Teensy and ![here](http://forum.pjrc.com/threads/21680-New-I2C-library-for-Teensy3?highlight=i2c_t3) for details.