Update to new build process and turn on lint.

[tannewt]

I haven't tested these changes on device yet. Please only merge you test it or I follow up later to say its tested.

For adafruit/circuitpython#475

[kattni]

The library doesn't work as it is - it returns all 0's for data. It doesn't work before your changes either though without the following alteration to line 179 in this section:

    def init(self, mode=NDOF_MODE):
        chip_id = self._read_register(_ID_REGISTER)
        if chip_id != _CHIP_ID:
            raise RuntimeError("bad chip id (%x != %x)" % (chip_id, _CHIP_ID))
        self.reset()
        self._write_register(_POWER_REGISTER, _POWER_NORMAL)
        self._write_register(_PAGE_REGISTER, 0x00)
        self._write_register(_TRIGGER_REGISTER, 0x00)
        time.sleep(0.01)
        self.switch_mode(mode)
        time.sleep(0.2)

Changing time.sleep to 0.2 resolves the issue and the sensor works. Basic testing on my part couldn't sort how to resolve it in the PR code. Adding @deshipu as a reviewer.

[deshipu]

The setting of mode and the delay after it are necessary for this sensor to work. Removing them breaks it.
You need to add this at the end:

        self.mode = NDOF_MODE
        time.sleep(0.2)

[tannewt]

Please re-review. I fixed up the __init__ method.

[tannewt]

Oops, wrong button. :-)

[kattni]

Tested successfully! Great job!