travis: use a newer Go version

jhenstridge · jhenstridge · commit 5b26438b00fb · 2020-11-22T15:53:40.000+08:00
diff --git a/.travis.yml b/.travis.yml
@@ -1,3 +1,6 @@
 language: go
 
+go:
+  - 1.14.x
+
 go_import_path: gopkg.in/check.v1

-Original file line number
+Diff line change
@@ @@ -1,3 +1,6 @@ @@
 language: go
 +go:
 +  - 1.14.x
++
 go_import_path: gopkg.in/check.v1