ci(travis): updates Android API level (apache#767)

Author: timbru31

.travis.yml

@@ -13,8 +13,8 @@ env:
   global:
     - SAUCE_USERNAME=snay
     - TRAVIS_NODE_VERSION=12
-    - ANDROID_API_LEVEL=28
-    - ANDROID_BUILD_TOOLS_VERSION=28.0.3
+    - ANDROID_API_LEVEL=29
+    - ANDROID_BUILD_TOOLS_VERSION=29.0.2
 
 language: node_js
 node_js: 12