travis: Windows build might be stuck as non-supported languages

tesuji · hellow554 · commit 71e7addba813 · 2019-10-21T10:33:05.000+02:00
See <https://docs.travis-ci.com/user/reference/windows/#supported-languages> for list of Windows supported languages.
diff --git a/.travis.yml b/.travis.yml
@@ -1,5 +1,5 @@
 dist: xenial
-language: minimal
+language: bash
 
 os:
   - linux
