update tests for finds_exact (#429)

Author: KazuCocoa

android_tests/lib/android/specs/common/element/window.rb

@@ -1,3 +1,4 @@
+# rake android[common/element/window]
 describe 'common/element/window' do
   t 'window_size' do
     wait do

ios_tests/lib/ios/specs/common/element/window.rb

@@ -1,3 +1,4 @@
+# rake ios[common/element/window]
 describe 'common/element/window' do
   def before_first
     screen.must_equal catalog

ios_tests/lib/ios/specs/ios/element/generic.rb

@@ -30,6 +30,8 @@ def verify(element)
   end
 
   t 'finds_exact' do
-    verify finds_exact uibutton_text
+    elements = finds_exact uibutton_text
+    elements.is_a?(Array).must_equal true
+    verify elements
   end
 end