Modernize and fix compilation

app/build.gradle

@@ -35,6 +35,7 @@ android {
 }
 
 dependencies {
+    compile 'com.android.support:design:26.0.1'
     testCompile 'junit:junit:4.12'
     testCompile 'org.robolectric:robolectric:3.4.2'
 }