Fix test with fraction exposure

sigal/image.py

@@ -255,7 +255,8 @@ def get_exif_tags(data):
         exptime = data['ExposureTime']
         if isinstance(exptime, tuple):
             try:
-                simple['exposure'] = str(fractions.Fraction(exptime[0], exptime[1]))
+                simple['exposure'] = str(fractions.Fraction(exptime[0],
+                                                            exptime[1]))
             except IndexError:
                 # Pillow == 3.0
                 simple['exposure'] = exptime[0]

tests/test_image.py

@@ -105,7 +105,10 @@ def test_get_exif_tags():
     assert simple['iso'] == 50
     assert simple['Make'] == 'NIKON'
     assert simple['datetime'] == 'Sunday, 22. January 2006'
-    assert simple['exposure'] == 0.00100603
+    if PIL.PILLOW_VERSION == '3.0.0':
+        assert simple['exposure'] == 0.00100603
+    else:
+        assert simple['exposure'] == '100603/100000000'
 
     data = {'FNumber': [1, 0], 'FocalLength': [1, 0], 'ExposureTime': 10}
     simple = get_exif_tags(data)