use 21.0 in travis script

goncalotomas · goncalotomas · commit 949922ab128e · 2018-09-25T16:48:42.000+01:00
diff --git a/.travis.yml b/.travis.yml
@@ -2,7 +2,7 @@ language: erlang
 otp_release:
   - 19.3
   - 20.3
-  - 21
+  - 21.0
 install:
   - make
 script:
