message: CI: Use ubuntu-18.04 for building release binaries
  The ubuntu-16.04 environment is being removed on Septemder 20, 2021.
diff: @@ -20,7 +20,7 @@ jobs:
  name: [linux, armv7, arm64, windows, macos]
  include:
  - name: linux
  - os: ubuntu-16.04
  + os: ubuntu-18.04
  build_deps: >
  libfuse-dev
  build_flags: --features mount
  @@ -28,7 +28,7 @@ jobs:
  asset_suffix: x86_64-linux.tar.gz
  - name: armv7
  - os: ubuntu-16.04
  + os: ubuntu-18.04
  target: armv7-unknown-linux-gnueabihf
  build_deps: >
  gcc-arm-linux-gnueabihf
  @@ -40,7 +40,7 @@ jobs:
  asset_suffix: armv7-linux.tar.gz
  - name: arm64
  - os: ubuntu-16.04
  + os: ubuntu-18.04
  target: aarch64-unknown-linux-gnu
  build_deps: >
  gcc-aarch64-linux-gnu
  