Bump Go to 1.15

martin-sucha · martin-sucha · commit f3b4598af73b · 2020-08-13T07:03:25.000+02:00
There have not been any changes in archive/zip, so just
bumping the supported Go version.
diff --git a/.travis.yml b/.travis.yml
@@ -1,8 +1,8 @@
 language: go
 
 go:
-- "1.13.x"
 - "1.14.x"
+- "1.15.x"
 - "master"
 
 env:
