Use the firefox addon in CI

https://docs.travis-ci.com/user/gui-and-headless-browsers/

Author: tomhoule

.travis.yml

@@ -4,20 +4,25 @@ rust:
   - beta
   - nightly
 cache: cargo
+addons:
+  firefox: latest
+before_install:
+  - if [ "$TRAVIS_RUST_VERSION" = "stable" ]; then (wget https://github.com/mozilla/geckodriver/releases/download/v0.23.0/geckodriver-v0.23.0-linux64.tar.gz) fi
+  - if [ "$TRAVIS_RUST_VERSION" = "stable" ]; then (mkdir geckodriver) fi
+  - if [ "$TRAVIS_RUST_VERSION" = "stable" ]; then (tar -xzf geckodriver-v0.23.0-linux64.tar.gz -C geckodriver) fi
+  - export PATH=$PATH:$PWD/geckodriver
 before_script:
   - sudo apt-get update
   - sudo apt-get install -y nodejs
   - npm i -g prettier
   - if [ "$TRAVIS_RUST_VERSION" = "stable" ]; then (rustup component add rustfmt-preview clippy-preview) fi
   - if [ "$TRAVIS_RUST_VERSION" = "stable" ]; then (rustup target add wasm32-unknown-unknown) fi
   - if [ "$TRAVIS_RUST_VERSION" = "stable" ]; then (cargo install -f wasm-bindgen-cli) fi
-  - if [ "$TRAVIS_RUST_VERSION" = "stable" ]; then (sudo apt-get install -y firefox) fi
-  - if [ "$TRAVIS_RUST_VERSION" = "stable" ]; then (./scripts/install_geckodriver.sh) fi
 script:
   - if [ "$TRAVIS_RUST_VERSION" = "stable" ]; then (cargo fmt --all -- --check) fi
   - if [ "$TRAVIS_RUST_VERSION" = "stable" ]; then (cargo clippy -- -D warnings) fi
   - prettier --debug-check -l './**/*.json' './**/*.graphql'
   - cargo test --all
   - cargo build --manifest-path=./graphql_client/examples/github/Cargo.toml
   - cargo build --manifest-path=./graphql_client_cli/Cargo.toml
-  - if [ "$TRAVIS_RUST_VERSION" = "stable" ]; then (GECKODRIVER=`pwd`/geckodriver cargo test --manifest-path=./graphql_client_web/Cargo.toml --target wasm32-unknown-unknown) fi
+  - if [ "$TRAVIS_RUST_VERSION" = "stable" ]; then (xvfb-run cargo test --manifest-path=./graphql_client_web/Cargo.toml --target wasm32-unknown-unknown) fi