Build nightly to fix CI

Author: jakelang

circle.yml

@@ -20,7 +20,7 @@ jobs:
              git diff --exit-code
       - run:
           name: Test
-          command: cargo test --target=x86_64-unknown-linux-gnu
+          command: cargo +nightly test --target=x86_64-unknown-linux-gnu
       - run:
-          name: Build
-          command: cargo build --release
+          name: Build Nightly
+          command: cargo +nightly build --release