Fix build script

.travis.yml

 matrix:
   include:
-    # Job 1) Run analyzer
-    - os: linux
-      sudo: false
-      addons:
-        apt:
-          # Flutter depends on /usr/lib/x86_64-linux-gnu/libstdc++.so.6 version GLIBCXX_3.4.18
-          sources:
-            - ubuntu-toolchain-r-test # if we don't specify this, the libstdc++6 we get is the wrong version
-          packages:
-            - libstdc++6
-            - fonts-droid
-      before_script:
-        - git clone https://github.com/flutter/flutter.git
-        - export PATH=`pwd`/flutter/bin:`pwd`/flutter/bin/cache/dart-sdk/bin:$PATH
-        - flutter doctor
-        - flutter packages get
-      script:
-        - flutter analyze
-    # Job 2) Check format and run tests
+    # Job 1) Check format and run tests
     - os: linux
       jdk: oraclejdk8
       sudo: false
@@ -33,12 +15,12 @@ matrix:
             - fonts-droid
             - clang-format-5.0
       before_script:
-        - git clone https://github.com/flutter/flutter.git
+        - git clone https://github.com/flutter/flutter.git --depth 1
         - export PATH=`pwd`/flutter/bin:`pwd`/flutter/bin/cache/dart-sdk/bin:$PATH
         - flutter doctor
       script:
         - ./scripts/format_code.sh
-    # Job 3) Build example APKs and run Java tests
+    # Job 2) Build example APKs and run Java tests
     - os: linux
       jdk: oraclejdk8
       sudo: false
@@ -52,20 +34,46 @@ matrix:
             - libstdc++6
             - fonts-droid
       before_script:
-        - ./script/before_build_apks.sh
+        - git clone https://github.com/flutter/flutter.git --depth 1
         - export ANDROID_HOME=`pwd`/android-sdk
         - export PATH=`pwd`/flutter/bin:`pwd`/flutter/bin/cache/dart-sdk/bin:$PATH
+        - wget https://dl.google.com/android/repository/sdk-tools-linux-3859397.zip
+        - mkdir android-sdk
+        - unzip -qq sdk-tools-linux-3859397.zip -d android-sdk
+        - export ANDROID_HOME=`pwd`/android-sdk
+        - export PATH=`pwd`/android-sdk/tools/bin:$PATH
+        - mkdir -p /home/travis/.android # silence sdkmanager warning
+        - echo 'count=0' > /home/travis/.android/repositories.cfg # silence sdkmanager warning
+        - echo y | sdkmanager "tools"
+        - echo y | sdkmanager "platform-tools"
+        - echo y | sdkmanager "build-tools;25.0.3"
+        - echo y | sdkmanager "platforms;android-25"
+        - echo y | sdkmanager "extras;android;m2repository"
+        - echo y | sdkmanager "extras;google;m2repository"
+        - echo y | sdkmanager "patcher;v4"
+        - sdkmanager --list
+        - wget http://services.gradle.org/distributions/gradle-3.5-bin.zip
+        - unzip -qq gradle-3.5-bin.zip
+        - export GRADLE_HOME=$PWD/gradle-3.5
+        - export PATH=$GRADLE_HOME/bin:$PATH
+        - gradle -v
+        - flutter doctor
       script:
-        - ./scripts/build.sh apk
-    # Job 4) Build example IPAs
+        - flutter build apk
+    # Job 3) Build example IPAs
     - os: osx
       language: generic
       osx_image: xcode9.3
       before_script:
-        - ./script/before_build_ipas.sh
+        - pip2 install six
+        - brew update
+        - brew install libimobiledevice
+        - brew install ideviceinstaller
+        - brew install ios-deploy
+        - git clone https://github.com/flutter/flutter.git --depth 1
         - export PATH=`pwd`/flutter/bin:`pwd`/flutter/bin/cache/dart-sdk/bin:$PATH
       script:
-        - ./scripts/build.sh ipa
+        - flutter build ios --no-codesign
 cache:
   directories:
     - $HOME/.pub-cache