added main and defined M_PI

Dependencies:   BNOWrapper

Revision:
6:faeba56869a5
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/BNOWrapper.lib	Tue Jul 30 18:34:06 2019 +0000
@@ -0,0 +1,1 @@
+https://os.mbed.com/teams/Affordable-Smart-Wheelchair/code/BNOWrapper/#9275e6f7bf1b