Fix misspellings

test/client/application/geary-application-test.vala

@@ -28,7 +28,7 @@ class GearyApplicationTest : TestCase {
     public void paths_when_installed() throws GLib.Error {
         string[] args = new string[] {
             _INSTALL_PREFIX + "/bin/geary",
-            // Specifiy this so the app doesn't actually attempt
+            // Specify this so the app doesn't actually attempt
             // to start up
             "-v"
         };

test/mock-object.vala

@@ -98,7 +98,7 @@ public class ExpectedCall : Object {
  * the code being tested. For example, if an object being tested
  * requires certain objects to be passed in via its constructor or as
  * arguments of method calls and uses these to implement its
- * behaviour, mock objects that fulfil these requirements can be used.
+ * behaviour, mock objects that fulfill these requirements can be used.
  *
  * Mock objects provide a means of both ensuring code being tested
  * makes expected method calls with expected arguments on its