bump msrv to 1.31.0 for editions

KodrAus · KodrAus · commit dc65e48bae6e · 2019-09-24T09:56:34.000+10:00
diff --git a/.travis.yml b/.travis.yml
@@ -1,7 +1,7 @@
 language: rust
 sudo: false
 rust:
-  - 1.28.0
+  - 1.31.0
   - stable
   - beta
   - nightly

-Original file line number
+Diff line change
@@ @@ -1,7 +1,7 @@ @@
 language: rust
 sudo: false
 rust:
 -  - 1.28.0
 +  - 1.31.0
   - stable
   - beta
   - nightly