Auto merge of #114 - mbrubeck:msrv, r=emilio

Test in Rust 1.20 on Travis

This will ensure we don't increase the minimum supported Rust version without noticing it.

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Author: bors-servo

.travis.yml

@@ -1,5 +1,6 @@
 language: rust
 rust:
+  - 1.20.0
   - nightly
   - beta
   - stable