diff --git a/android/app/build.gradle b/android/app/build.gradle
index 9912497c..d03b076c 100644
--- a/android/app/build.gradle
+++ b/android/app/build.gradle
@@ -14,9 +14,9 @@ if (flutterRoot == null) {
 apply plugin: 'com.android.application'
 apply from: "$flutterRoot/packages/flutter_tools/gradle/flutter.gradle"
 
-def keystorePropertiesFile = rootProject.file("key.properties")
-def keystoreProperties = new Properties()
-keystoreProperties.load(new FileInputStream(keystorePropertiesFile))
+//def keystorePropertiesFile = rootProject.file("key.properties")
+//def keystoreProperties = new Properties()
+//keystoreProperties.load(new FileInputStream(keystorePropertiesFile))
 
 android {
     compileSdkVersion 27
@@ -36,19 +36,19 @@ android {
         testInstrumentationRunner "android.support.test.runner.AndroidJUnitRunner"
     }
 
-    signingConfigs {
-        release {
-            keyAlias keystoreProperties['keyAlias']
-            keyPassword keystoreProperties['keyPassword']
-            storeFile file(keystoreProperties['storeFile'])
-            storePassword keystoreProperties['storePassword']
-        }
-    }
+//    signingConfigs {
+//        release {
+//            keyAlias keystoreProperties['keyAlias']
+//            keyPassword keystoreProperties['keyPassword']
+//            storeFile file(keystoreProperties['storeFile'])
+//            storePassword keystoreProperties['storePassword']
+//        }
+//    }
 
     buildTypes {
         release {
             // Signing with the debug keys for now, so `flutter run --release` works.
-            signingConfig signingConfigs.release
+//            signingConfig signingConfigs.release
         }
 
         profile {
@@ -67,4 +67,4 @@ dependencies {
     androidTestImplementation 'com.android.support.test.espresso:espresso-core:3.0.1'
 }
 
-apply plugin: 'com.google.gms.google-services'
\ No newline at end of file
+apply plugin: 'com.google.gms.google-services'
diff --git a/lib/i18n/strings.dart b/lib/i18n/strings.dart
index 65ceb8ee..24cc57ed 100644
--- a/lib/i18n/strings.dart
+++ b/lib/i18n/strings.dart
@@ -9,7 +9,7 @@ class Strings {
     final String name =
         locale.countryCode.isEmpty ? locale.languageCode : locale.toString();
     final String localeName = Intl.canonicalizedLocale(name);
-    return initializeMessages(localeName).then((Null _) {
+    return initializeMessages(localeName).then((dynamic _) {
       Intl.defaultLocale = localeName;
       return new Strings();
     });
diff --git a/lib/models/session.dart b/lib/models/session.dart
index 5fdad75a..7bec1d5c 100644
--- a/lib/models/session.dart
+++ b/lib/models/session.dart
@@ -50,7 +50,7 @@ class Session {
     var endsAt = DateTime.parse(json['endsAt']);
     var isServiceSession = json['isServiceSession'];
     var isPlenumSession = json['isPlenumSession'];
-    var speakers = [];
+    List<Speaker> speakers = [];
     var room = roomMap[json['roomId']];
 
     DurationType durationType;
diff --git a/lib/models/speaker.dart b/lib/models/speaker.dart
index 381b76b2..fcac27a8 100644
--- a/lib/models/speaker.dart
+++ b/lib/models/speaker.dart
@@ -35,12 +35,12 @@ class Speaker {
     var isTopSpeaker = json['isTopSpeaker'];
     var fullName = json['fullName'];
 
-    var sessions = [];
+    List<Session> sessions = [];
     for (var sessionId in json['sessions']) {
       sessions.add(sessionMap[sessionId]);
     }
 
-    var links = [];
+    List<Link> links = [];
     for (var link in json['links']) {
       links.add(Link.fromJson(link));
     }
diff --git a/pubspec.yaml b/pubspec.yaml
index 27f7cc03..0fb23d63 100644
--- a/pubspec.yaml
+++ b/pubspec.yaml
@@ -12,11 +12,11 @@ dependencies:
   uri: 0.7.0 # flutter_test depends on this version
   url_launcher: "^2.0.1"
 
-  google_sign_in: 2.0.1
+  google_sign_in: 2.1.1
   firebase_auth: 0.4.3
   firebase_analytics: 0.2.2
-  cloud_firestore: 0.2.6
-  shared_preferences: 0.3.2
+  cloud_firestore: 0.2.9
+  shared_preferences: 0.3.3
 
   # The following adds the Cupertino Icons font to your application.
   # Use with the CupertinoIcons class for iOS style icons.
@@ -27,6 +27,7 @@ dependencies:
 dev_dependencies:
   flutter_test:
     sdk: flutter
+  mockito: 2.2.3
 
 
 # For information on the generic Dart part of this file, see the