Remove very old travis badge from readme #763

Job	Run time
Mac-os	3m 15s
Linux-musl (x86_64-linux-musl)	2m 6s
Android (21.4.7075529)	2m 52s
Linux-musl (aarch64-linux-musl)	2m 14s
Linux-musl-apicheck (x86_64-linux-musl)	2m 8s
Android (16.1.4479499)	3m 21s
Mac-os-aarch64	13s
Android (26.1.10909125)	2m 4s
Mac-os-aarch64-cctools	2m 41s
Mac-os-cctools	2m 46s
Windows	1m 58s
Mac-os-universal-cctools	12s
Mac-os-universal	0s
Notify-success	3s
	25m 53s

Provide feedback