Fix Appveyor CI (#130)

New cordova-android@6.1.1 requires Android SDK 25 but it causes a build to last ~25 minutes for some reason. Using SDK 24 and cordova-android@6.0.0 fixes that.

appveyor.yml

@@ -1,7 +1,18 @@
 
 # Copyright (c) Microsoft Open Technologies, Inc.  All rights reserved.  Licensed under the Apache License, Version 2.0.  See License.txt in the project root for license information.
 
+environment:
+  ANDROID_HOME: "C:\\android-sdk-windows"
+  JAVA_HOME: "C:\\Program Files\\Java\\jdk1.8.0"
+
+init:
+  - cd \
+  - appveyor DownloadFile https://dl.google.com/android/android-sdk_r24.3.4-windows.zip
+  - 7z x android-sdk_r24.3.4-windows.zip > nul
+  - cd C:\projects\azure-activedirectory-library-for-cordova
+
 install:
+  - echo y | "%ANDROID_HOME%\tools\android.bat" --silent update sdk --no-ui --all --filter android-24,platform-tools,tools,build-tools-24.0.0,extra-google-m2repository,extra-android-m2repository
   - npm install -g cordova
 # we install paramedic from git repo as we require support for extra args
 # to run different target windows platform which is not released yet.
@@ -16,4 +27,4 @@ test_script:
   - cordova-paramedic --config .\tests\paramedic-configs\.paramedic.config.win81.js
   - cordova-paramedic --config .\tests\paramedic-configs\.paramedic.config.win10.js
   - cordova-paramedic --config .\tests\paramedic-configs\.paramedic.config.wp81.js
-  - cordova-paramedic --platform android --plugin . --justbuild
+  - cordova-paramedic --platform android@6.0.0 --plugin . --justbuild