add travis deploy task for fdroid #5

pushes build result of platforms/android to `fdroid` branch,
so fdroid can build using a standard gradle project.

TODO: re-enable `on: tags` build option after testing

.travis.yml

@@ -1,22 +1,28 @@
-language: node_js
+language: android
 node_js:
 - "8"
 
-branches:
-  only:
-  - master
-
 before_script:
 - npm install
+- npm install -g ionic cordova
 
 script:
 - npm run build
+- npm run android:build
 
 deploy:
-  provider: pages
-  skip-cleanup: true
-  github-token: $GITHUB_TOKEN 
-  keep-history: true
-  on:
-    tags: true
-  local_dir: www
+  # deploy web build to gh-pages branch
+  - provider: pages
+    skip-cleanup: true
+    github-token: $GITHUB_TOKEN
+    keep-history: true
+    #on:
+    #  tags: true
+    local_dir: www
+
+  # deploy android project for fdroid builds
+  - provider: script
+    script: bash tools/deploy-fdroid.sh
+    skip-cleanup: true
+    #on:
+    #  tags: true

tools/deploy-fdroid.sh

@@ -0,0 +1,15 @@
+#!/bin/bash
+# expects travis env vars: $repo, $tag, $rev, $GITHUB_TOKEN
+
+target=https://$GITHUB_TOKEN@github.com/sensebox/blockly-app.git
+branch=fdroid
+
+git clone --depth=1 -b $target $repo fdroid
+rm -rf fdroid/*
+mv -f platforms/android fdroid/
+cd fdroid
+git config user.name "Travis-CI"
+git config user.email "travis@travis-ci.org"
+git add -f --ignore-errors .
+git commit -m "android project for $tag at $rev" --amend # dont add new commits to avoid increasing repo size
+git push -f $target $branch > /dev/null 2>&1 # hide output to not leak GITHUB_TOKEN in logs