Small typo in library

[hamzaMahdi]

MPU6050-I2C-Python-Class/MPU6050.py

Line 810 in 1cd8bf5

y = ctypes.c_int16(a_v_raw.y - (a_grav.y*8192)).value

Hey, this is an awesome library! It really needs more recognition. I found a small typo in the above link where the y acceleration is copied twice instead of calculating the z accel.