update travis go version to 1.13

cha87de · cha87de · commit bf371e1f0c4d · 2020-02-24T14:39:43.000+01:00
diff --git a/.travis.yml b/.travis.yml
@@ -1,6 +1,6 @@
 language: go
 go:
-  - '1.11.5'
+  - '1.13' 
 
 before_install:
   - sudo apt-get -qq update
