See if it can run on macOS

.github/workflows/rust.yml

@@ -9,18 +9,19 @@ on:
 jobs:
   build-and-test:
 
-    runs-on: ubuntu-latest
+    runs-on: macOS-latest
     env:
       PYENV_VERSION: "2.7.13"
       PYENV_ROOT: $HOME/.pyenv
 
     steps:
     - uses: actions/checkout@v2
-    - name: Prepare build system
-      run: |
-        sudo apt-get install -y make build-essential libssl-dev zlib1g-dev libbz2-dev \
-          libreadline-dev libsqlite3-dev wget curl llvm libncurses5-dev libncursesw5-dev \
-          xz-utils tk-dev libffi-dev liblzma-dev
+    - name: Install stable toolchain
+      uses: actions-rs/toolchain@v1
+      with:
+        profile: minimal
+        toolchain: stable
+        override: true
     - name: Prepare python
       run: |
         curl https://pyenv.run | bash