mergify: Add 5.15 rule#12743

Merged

0xc0170 merged 2 commits intoARMmbed:masterfrom

0xc0170:fix_mergify_5.15

Apr 2, 2020

Commits on Apr 1, 2020

mergify: remove spaces
0xc0170
committed

Commits on Apr 2, 2020

mergify: add 5.15 branch rule
0xc0170
committed