Benchmark comparison of MicroPython boards

[ckuehnel]

PyStone result for MAiX BiT w/ MicroPython v0.1.1 (CPU clock 403 MHz):

>>> os.uname()
(sysname='MaixPy', nodename='MaixPy', release='0.1.1', version='v0.1.1 on 2019-02-20', machine='Sipeed_M1 with kendryte-k210')

>>> exec(open('pystone_lowmem.py').read())
Pystone(1.2) time for 500 passes = 98 ms
This machine benchmarks at 5102 pystones/second

[rcolistete]

Thanks, so I've updated the 1st post with benchmarks on Pyboard D, ESP32 and MAiX BiT.