add twilio shoutout to registration

// FREEBIE

res/layout/registration_activity.xml

@@ -93,5 +93,13 @@
                     android:textAppearance="?android:attr/textAppearanceMedium"/>
         </LinearLayout>
 
+        <ImageView android:id="@+id/twilio_shoutout"
+                   android:layout_width="wrap_content"
+                   android:layout_height="wrap_content"
+                   android:src="@drawable/ic_twilio_shoutout_white"
+                   android:layout_gravity="right"
+                   android:tint="@color/grey_800"
+                   android:contentDescription="@string/registration_activity__powered_by_twilio"/>
+
     </LinearLayout>
 </ScrollView>

res/values/strings.xml

@@ -632,6 +632,7 @@
     <string name="registration_activity__phone_number">PHONE NUMBER</string>
     <string name="registration_activity__register">Register</string>
     <string name="registration_activity__registration_will_transmit_some_contact_information_to_the_server_temporariliy">Registration transmits some contact information to the server. It is not stored.</string>
+    <string name="registration_activity__powered_by_twilio">Powered by twilio</string>
 
     <!-- registration_problems -->
     <string name="registration_problems__some_possible_problems_include">Some possible problems
@@ -980,7 +981,6 @@
     <string name="transport_selection_list_item__transport_icon">Transport icon</string>
 
 
-
     <!-- EOF -->
 
 </resources>