message: ci: update travis toolchains
  This cleans up and updates travis configuration, adding some more jobs
  and bumping to latest toolchains.
diff: +---
  language: rust
  -rust:
  - - 1.39.0 # minimum supported toolchain
  - - 1.41.0 # pinned toolchain for clippy
  - - stable
  - - beta
  - - nightly
  +os: linux
  -matrix:
  +jobs:
  allow_failures:
  - rust: nightly
  -
  -before_script:
  - - bash -c 'if [[ "$TRAVIS_RUST_VERSION" == "$CLIPPY_RUST_VERSION" ]]; then
  - rustup component add clippy;
  - fi'
  -
  -env:
  - global:
  - - CLIPPY_RUST_VERSION=1.41.0
  -
  + include:
  + - name: "Test with nightly toolchain"
  + arch: amd64
  + rust: nightly
  + script:
  + - cargo test
  + - name: "Test with beta toolchain"
  + arch: amd64
  + rust: beta
  + script:
  + - cargo test
  + - name: "Test with stable toolchain"
  + arch: amd64
  + rust: stable
  + script:
  + - cargo test
  + - cargo test --features failpoints
  + - name: "Test a secondary architecture (aarch64)"
  + arch: arm64
  + rust: stable
  script:
  - cargo test
  - cargo test --features failpoints
  - - bash -c 'if [[ "$TRAVIS_RUST_VERSION" == "$CLIPPY_RUST_VERSION" ]]; then
  - cargo clippy -- -D warnings;
  - fi'
  + - name: "Test with minimum supported toolchain"
  + arch: amd64
  + rust: 1.39.0
  + script:
  + - cargo test --release
  + - name: "Lints with pinned toolchain"
  + arch: amd64
  + rust: 1.44.0
  + before_script:
  + - rustup component add clippy
  + - rustup component add rustfmt
  + script:
  + - cargo clippy -- -D warnings
  + - cargo fmt -- --check -l
  