Enable stable Rust again

.travis.yml

@@ -25,14 +25,12 @@ matrix:
         - cd plugin
         - luacov-coveralls -e $TRAVIS_BUILD_DIR/lua_install
 
-    # Stable builds can be re-enabled after 2018-12-06, when Rust 1.31 is stable
+    - language: rust
+      rust: stable
 
-    # - language: rust
-    #   rust: stable
-
-    #   script:
-    #     - cd server
-    #     - cargo test --verbose
+      script:
+        - cd server
+        - cargo test --verbose
 
     - language: rust
       rust: beta

README.md

@@ -57,8 +57,6 @@ If you use a plugin that _isn't_ Rojo for syncing code, open an issue and let me
 ## Contributing
 The `master` branch is a rewrite known as **Epiphany**. It includes a breaking change to the project configuration format and an infrastructure overhaul.
 
-Building Rojo requires the latest Rust beta in order to use **2018 Edition** features. Once Rust 1.31 is stable on **December 6, 2018**, Rojo `master` will compile on Rust stable again.
-
 Pull requests are welcome!
 
 All pull requests are run against a test suite on Travis CI. That test suite should always pass!