Merge pull request commons-app#925 from whym/travis

travis-ci: explicit license acceptance; android-26

Author: neslihanturan

.travis.yml

@@ -24,7 +24,10 @@ android:
     - extra-android-m2repository
     - ${ANDROID_TARGET}
     - android-25
+    - android-26
     - sys-img-${ANDROID_ABI}-${ANDROID_TARGET}
+  licenses:
+    - 'android-sdk-license-.+'
 
 before_script:
   - echo no | android create avd --force -n test -t $ANDROID_TARGET --abi $ANDROID_ABI