Selecting a microSD card

TODO: explain microSDHC, class 2/4/6/10, UHS-I/II/III, U1/3, 500/633/1000x and why these don't really matter (sequential vs. random)

TODO: It looks like there are some new ratings for Application Performance Class - this looks useful.

It looks like this article has some helpful information: http://www.theatreofnoise.com/2013/08/choosing-micro-sd-card-for-your-phone.html

Benchmarks:

• https://lechnology.com/2017/04/microsd-card-benchmark-for-ev3-and-raspberry-pi-3/
• http://www.pidramble.com/wiki/benchmarks/microsd-cards
• http://jgp.net/microsd-card-performance-raspberry-pi/