Delete .travis.yml

Removing Travis CI as ASF Infra has decided to move away from Travis.
diff --git a/.travis.yml b/.travis.yml
deleted file mode 100644
index 4afbd4b..0000000
--- a/.travis.yml
+++ /dev/null
@@ -1,47 +0,0 @@
-#
-# Licensed to the Apache Software Foundation (ASF) under one
-# or more contributor license agreements.  See the NOTICE file
-# distributed with this work for additional information
-# regarding copyright ownership.  The ASF licenses this file
-# to you under the Apache License, Version 2.0 (the
-# "License"); you may not use this file except in compliance
-# with the License.  You may obtain a copy of the License at
-#
-#   http://www.apache.org/licenses/LICENSE-2.0
-#
-# Unless required by applicable law or agreed to in writing,
-# software distributed under the License is distributed on an
-# "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
-# KIND, either express or implied.  See the License for the
-# specific language governing permissions and limitations
-# under the License.
-#
-
-sudo: required
-
-dist: trusty
-
-language: node_js
-
-node_js:
-- '6.9.4'
-
-branches:
-  only:
-    - develop
-
-before_script:
-  - export CHROME_BIN=chromium-browser
-  - export DISPLAY=:99.0
-  - sh -e /etc/init.d/xvfb start
-
-install:
-  - npm install
-
-script:
-  - npm run tslint
-  - npm run test
-  - npm run build
-
-notifications:
-  email: false