Use Time.utc instead of Time.local in tests

Due to the use of Time.local in a GMT+2 TZ, the expected date must
have 2 hours subtracted to be the correct expected utc time.

Test should now pass when run anywhere.

test/test_date_ext.rb

@@ -10,13 +10,13 @@ def setup
   end
 
   def test_sunrise
-    sunrise = Time.mktime(2009, 7, 23, 4, 50, 32)
+    sunrise = Time.utc(2009, 7, 23, 2, 50, 32)
     assert_equal(sunrise, @date.sunrise(@lat, @lng))
   end
 
   def test_sunset
-    sunset =  Time.mktime(2009, 7, 23, 21, 48, 56)
+    sunset =  Time.utc(2009, 7, 23, 19, 48, 56)
 
     assert_equal(sunset, @date.sunset(@lat, @lng))
   end
-end
+end

test/test_sun_time.rb

@@ -11,13 +11,13 @@ def setup
   end
 
   def test_sunrise
-    sunrise = Time.mktime(2009, 7, 23, 4, 50, 32)
+    sunrise = Time.utc(2009, 7, 23, 2, 50, 32)
 
     assert_equal(sunrise, @sun_time.sunrise)
   end
 
   def test_sunset
-    sunset =  Time.mktime(2009, 7, 23, 21, 48, 56)
+    sunset =  Time.utc(2009, 7, 23, 19, 48, 56)
 
     assert_equal(sunset, @sun_time.sunset)
   end
@@ -79,4 +79,4 @@ def test_j_set
   def test_j_rise
     assert_in_delta(2455035.6184334, @sun_time.send(:j_rise), 2 ** -20)
   end
-end
+end