Update stable library feature list by Travis CI build 1531

Author: Travis CI

stable_library_feature.txt

@@ -135,7 +135,7 @@ cow_from_vec                      1.8.0   2017-05-20 08:38:39 +0100  2017-05-20
 mpsc_debug                        1.8.0   2017-05-20 08:38:39 +0100  2017-05-20 08:38:39 +0100
 encode_utf16                      1.8.0   2018-04-07 21:56:02 +0200  2020-09-04 08:46:47 +0000
 str_parse_error2                  1.8.0   2019-12-11 09:49:29 -0500  2019-12-11 09:49:29 -0500
-net2_mutators                     1.9.0   2016-02-27 14:15:19 -0800  2016-02-27 14:15:19 -0800
+net2_mutators                     1.9.0   2016-02-27 15:02:48 -0800  2016-02-27 15:02:48 -0800
 from_slice_v4                     1.9.0   2016-03-04 14:12:18 -0800  2016-03-04 14:12:18 -0800
 core_impl_debug                   1.9.0   2016-03-04 18:49:43 -0800  2020-09-03 15:51:57 +0000
 ipv6_from_octets                  1.9.0   2016-03-18 13:53:40 +0100  2016-03-18 13:53:40 +0100