Update stable library feature list by Travis CI build 1515

Author: Travis CI

stable_library_feature.txt

@@ -126,7 +126,7 @@ cmp_os_str                        1.8.0   2016-02-18 16:03:42 +0200  2016-02-18
 cow_os_str_as_ref_path            1.8.0   2016-02-18 16:04:28 +0200  2016-02-18 16:04:28 +0200
 cmp_path                          1.8.0   2016-02-18 16:07:12 +0200  2016-02-18 16:07:12 +0200
 cell_map                          1.8.0   2016-02-25 15:52:29 -0800  2016-02-25 15:52:29 -0800
-op_assign_traits                  1.8.0   2016-02-25 15:52:29 -0800  2017-06-07 22:04:46 -0400
+op_assign_traits                  1.8.0   2016-02-25 15:52:29 -0800  2017-06-07 22:08:14 -0400
 time2                             1.8.0   2016-02-25 15:52:29 -0800  2016-02-25 15:52:29 -0800
 pthread_t                         1.8.0   2016-06-21 10:14:16 -0700  2020-04-13 23:37:22 +0000
 drop_in_place                     1.8.0   2017-03-14 01:08:21 +0200  2017-03-14 01:08:21 +0200