travis: Remove Ruby 2.4 entry

cosmo0920 · cosmo0920 · commit 10c41b5a3cd3 · 2021-04-20T10:26:47.000+09:00
Signed-off-by: Hiroshi Hatake &lt;hatake@calyptia.com&gt;
diff --git a/.travis.yml b/.travis.yml
@@ -5,7 +5,6 @@ addons:
   postgresql: "9.4"
 
 rvm:
-  - 2.4.10
   - 2.5.8
   - 2.6.6
   - 2.7.1

-Original file line number
+Diff line change
   postgresql: "9.4"
 rvm:
 -  - 2.4.10
   - 2.5.8
   - 2.6.6
   - 2.7.1