message: Upgrade Rust version for CI.
diff: @@ -15,7 +15,7 @@ jobs:
  uses: actions-rs/toolchain@v1
  with:
  profile: minimal
  - toolchain: nightly-2019-12-19
  + toolchain: nightly-2020-06-09
  override: true
  components: rustfmt, clippy
  - run: make lint
  @@ -29,7 +29,7 @@ jobs:
  # uses: actions-rs/toolchain@v1
  # with:
  # profile: minimal
  - # toolchain: nightly-2019-12-19
  + # toolchain: nightly-2020-06-09
  # override: true
  # components: rustfmt, clippy
  # - run: make doc-local
  @@ -44,13 +44,13 @@ jobs:
  include:
  - build: linux
  os: ubuntu-latest
  - rust: nightly-2019-12-19
  + rust: nightly-2020-06-09
  - build: macos
  os: macos-latest
  - rust: nightly-2019-12-19
  + rust: nightly-2020-06-09
  - build: windows
  os: windows-latest
  - rust: nightly-2019-12-19
  + rust: nightly-2020-06-09
  steps:
  - uses: actions/checkout@v2
  - name: Install Rust ${{ matrix.rust }}
  