removes redundant travis config file (#4201)

.travis.yml

@@ -1,31 +0,0 @@
-language: node_js
-node_js: [node]
-
-before_install:
-  # Export the C++11 compiler.
-  - if [[ $TRAVIS_OS_NAME == "linux" ]]; then export CXX=g++-4.8; fi
-
-cache: yarn
-
-env:
-  # Do multiple runs for testing and linting.
-  matrix:
-    - TEST_TYPE=test
-    - TEST_TYPE=lint:eslint
-    - TEST_TYPE=lint:prettier
-
-before_script:
-  # When linting, build the dependencies so they can be resolved.
-  - |
-    set -e
-    if [[ $TEST_TYPE == 'lint:eslint' ]]; then
-      yarn build
-    fi
-    set +e
-
-script:
-  # Run testing or linting depending on the environment.
-  - |
-    set -e
-    yarn $TEST_TYPE
-    set +e