Introduce WorkManager dependency

Guava needs to be excluded because google-api-client already imports it.

build.gradle

@@ -47,11 +47,9 @@ task checkTests(type: GradleBuild) {
 }
 
 ext {
-    // Play Services is a big download so it should only be upgraded if necessary and after
-    // community discussion and a warning period.
-
     supportLibraryVersion = '27.1.1'
     leakyCanaryVersion = '1.5.4'
     daggerVersion = '2.16'
     rxLifecycleVersion = '2.2.1'
+    workManagerVersion = "1.0.0-alpha10"
 }

collect_app/build.gradle

@@ -270,6 +270,15 @@ dependencies {
     implementation "com.trello.rxlifecycle2:rxlifecycle-android:${rootProject.rxLifecycleVersion}"
     implementation "com.trello.rxlifecycle2:rxlifecycle-android-lifecycle:${rootProject.rxLifecycleVersion}"
 
+    // WorkManager for specifying deferrable, asynchronous tasks
+    implementation("android.arch.work:work-runtime:${rootProject.workManagerVersion}") {
+        exclude group: 'com.google.guava', module: 'listenablefuture'
+    }
+    // Optional JobDispatcher support so devices with Play Services do better than AlarmManager
+    implementation("android.arch.work:work-firebase:${rootProject.workManagerVersion}") {
+        exclude group: 'com.google.guava', module: 'listenablefuture'
+    }
+
     // Makes binding to Views easy:
     implementation "com.jakewharton:butterknife:8.8.1"
     annotationProcessor "com.jakewharton:butterknife-compiler:8.8.1"
@@ -304,6 +313,7 @@ dependencies {
 
     androidTestImplementation "com.squareup.okhttp3:mockwebserver:3.9.0"
 
+    androidTestImplementation "android.arch.work:work-testing:${rootProject.workManagerVersion}"
 }
 
 // Must be at bottom to prevent dependency collisions