Fix CI: add suggestion by @mattico

Disasm · Disasm · commit e4cff7f75354 · 2021-03-12T07:20:51.000+03:00
diff --git a/.travis.yml b/.travis.yml
@@ -4,6 +4,11 @@ rust:
   - nightly
   - stable
 
+matrix:
+  fast_finish: true
+  allow_failures:
+    - rust: nightly
+
 cache: cargo
 
 install:
