ci: remove travis & appveyor (apache#906)

Author: erisu

.appveyor.yml

@@ -1,3 +1,2 @@
 .*
-appveyor.yml
 tests

.npmignore

@@ -21,9 +21,6 @@ description: Open an in-app browser window.
 #         under the License.
 -->
 
-|AppVeyor|Travis CI|
-|:-:|:-:|
-|[![Build status](https://ci.appveyor.com/api/projects/status/github/apache/cordova-plugin-inappbrowser?branch=master)](https://ci.appveyor.com/project/ApacheSoftwareFoundation/cordova-plugin-inappbrowser)|[![Build Status](https://travis-ci.org/apache/cordova-plugin-inappbrowser.svg?branch=master)](https://travis-ci.org/apache/cordova-plugin-inappbrowser)|
 
 # cordova-plugin-inappbrowser