Update travis configuration

Use multiple language support

Author: maxymshg

.travis.yml

@@ -1,18 +1,19 @@
-language: rust
+language: rust, node_js
 rust:
   - stable
   - beta
   - nightly
+node_js:
+  - "lts/*"
+  - "8"
 cache: cargo
 before_script:
-  - sudo apt-get update
-  - sudo apt-get install -y nodejs
   - npm i -g prettier
   - if [ "$TRAVIS_RUST_VERSION" = "stable" ]; then (rustup component add rustfmt-preview clippy-preview) fi
 script:
   - if [ "$TRAVIS_RUST_VERSION" = "stable" ]; then (cargo fmt --all -- --check) fi
   - if [ "$TRAVIS_RUST_VERSION" = "stable" ]; then (cargo clippy) fi
-  - prettier --debug-check -l './**/*.json'
+  - 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