Bump postgrex from 0.15.3 to 0.15.5

Bumps [postgrex](https://github.com/elixir-ecto/postgrex) from 0.15.3 to 0.15.5.
- [Release notes](https://github.com/elixir-ecto/postgrex/releases)
- [Changelog](https://github.com/elixir-ecto/postgrex/blob/master/CHANGELOG.md)
- [Commits](elixir-ecto/postgrex@v0.15.3...v0.15.5)

Signed-off-by: dependabot-preview[bot] <support@dependabot.com>

mix.lock

@@ -22,7 +22,7 @@
   "mimerl": {:hex, :mimerl, "1.2.0", "67e2d3f571088d5cfd3e550c383094b47159f3eee8ffa08e64106cdf5e981be3", [:rebar3], [], "hexpm", "f278585650aa581986264638ebf698f8bb19df297f66ad91b18910dfc6e19323"},
   "nimble_parsec": {:hex, :nimble_parsec, "0.5.3", "def21c10a9ed70ce22754fdeea0810dafd53c2db3219a0cd54cf5526377af1c6", [], [], "hexpm", "589b5af56f4afca65217a1f3eb3fee7e79b09c40c742fddc1c312b3ac0b3399f"},
   "parse_trans": {:hex, :parse_trans, "3.3.0", "09765507a3c7590a784615cfd421d101aec25098d50b89d7aa1d66646bc571c1", [:rebar3], [], "hexpm", "17ef63abde837ad30680ea7f857dd9e7ced9476cdd7b0394432af4bfc241b960"},
-  "postgrex": {:hex, :postgrex, "0.15.3", "5806baa8a19a68c4d07c7a624ccdb9b57e89cbc573f1b98099e3741214746ae4", [:mix], [{:connection, "~> 1.0", [hex: :connection, repo: "hexpm", optional: false]}, {:db_connection, "~> 2.1", [hex: :db_connection, repo: "hexpm", optional: false]}, {:decimal, "~> 1.5", [hex: :decimal, repo: "hexpm", optional: false]}, {:jason, "~> 1.0", [hex: :jason, repo: "hexpm", optional: true]}], "hexpm", "4737ce62a31747b4c63c12b20c62307e51bb4fcd730ca0c32c280991e0606c90"},
+  "postgrex": {:hex, :postgrex, "0.15.5", "aec40306a622d459b01bff890fa42f1430dac61593b122754144ad9033a2152f", [:mix], [{:connection, "~> 1.0", [hex: :connection, repo: "hexpm", optional: false]}, {:db_connection, "~> 2.1", [hex: :db_connection, repo: "hexpm", optional: false]}, {:decimal, "~> 1.5", [hex: :decimal, repo: "hexpm", optional: false]}, {:jason, "~> 1.0", [hex: :jason, repo: "hexpm", optional: true]}], "hexpm", "ed90c81e1525f65a2ba2279dbcebf030d6d13328daa2f8088b9661eb9143af7f"},
   "ssl_verify_fun": {:hex, :ssl_verify_fun, "1.1.5", "6eaf7ad16cb568bb01753dbbd7a95ff8b91c7979482b95f38443fe2c8852a79b", [:make, :mix, :rebar3], [], "hexpm", "13104d7897e38ed7f044c4de953a6c28597d1c952075eb2e328bc6d6f2bfc496"},
   "telemetry": {:hex, :telemetry, "0.4.0", "8339bee3fa8b91cb84d14c2935f8ecf399ccd87301ad6da6b71c09553834b2ab", [:rebar3], [], "hexpm", "e9e3cacfd37c1531c0ca70ca7c0c30ce2dbb02998a4f7719de180fe63f8d41e4"},
   "unicode_util_compat": {:hex, :unicode_util_compat, "0.4.1", "d869e4c68901dd9531385bb0c8c40444ebf624e60b6962d95952775cac5e90cd", [:rebar3], [], "hexpm", "1d1848c40487cdb0b30e8ed975e34e025860c02e419cb615d255849f3427439d"},