updated for mbed-os 5.5

Fork of Task324Solution by Nicholas Outram

Changes

RevisionDateWhoCommit message
3:2f6da507b847 2019-10-07 noutram 2019 default tip
2:e4bdd0f14c27 2019-10-07 noutram Typo fixed
1:9026e1e25f5c 2019-09-11 noutram 2019;
0:3590cc227050 2017-07-13 noutram updated for mbed-os 5.5