rebar.lock: Restore the pinning of horus

[Why]
It was lost because I was using a `_checkouts` dependency...

Author: dumbbell

rebar.lock

@@ -1,17 +1,20 @@
 {"1.2.0",
 [{<<"aten">>,{pkg,<<"aten">>,<<"0.6.0">>},1},
  {<<"gen_batch_server">>,{pkg,<<"gen_batch_server">>,<<"0.8.9">>},1},
+ {<<"horus">>,{pkg,<<"horus">>,<<"0.3.1">>},0},
  {<<"ra">>,{pkg,<<"ra">>,<<"2.16.12">>},0},
  {<<"seshat">>,{pkg,<<"seshat">>,<<"0.6.0">>},1}]}.
 [
 {pkg_hash,[
  {<<"aten">>, <<"7A57B275A6DAF515AC3683FB9853E280B4D0DCDD74292FD66AC4A01C8694F8C7">>},
  {<<"gen_batch_server">>, <<"1C6BC0F530BF8C17E8B4ACC20C2CC369FFA5BEE2B46DE01E21410745F24B1BC9">>},
+ {<<"horus">>, <<"A5274C96E15924C28413752617B06050E4B08C04628B88209AFF9EA076F2BCB5">>},
  {<<"ra">>, <<"D97D0213E38C7D334128AA31940444EBFEEF3D370BA5F4ACC08D2BFBCC4979E9">>},
  {<<"seshat">>, <<"3172EB1D7A2A4F66108CD6933A4E465AFF80F84AA90ED83F047B92F636123CCD">>}]},
 {pkg_hash_ext,[
  {<<"aten">>, <<"5F39A164206AE3F211EF5880B1F7819415686436E3229D30B6A058564FBAA168">>},
  {<<"gen_batch_server">>, <<"C8581FE4A4B6BCCF91E53CE6A8C7E6C27C8C591BAB5408B160166463F5579C22">>},
+ {<<"horus">>, <<"D564D30EBC274F0D92C3D44A336D0B892F000BE159912AE4E6838701E85495EC">>},
  {<<"ra">>, <<"8A8F1A05250F9E91E253FD6CEE13A3551ECB2B10295D2E35233A3C0FE8EC2459">>},
  {<<"seshat">>, <<"7CEF700F92831DD7CAE6A6DD223CCC55AC88ECCE0631EE9AB0F2B5FB70E79B90">>}]}
 ].