Bump postgrex from 0.15.5 to 0.15.6

Bumps [postgrex](https://github.com/elixir-ecto/postgrex) from 0.15.5 to 0.15.6.
- [Release notes](https://github.com/elixir-ecto/postgrex/releases)
- [Changelog](https://github.com/elixir-ecto/postgrex/blob/master/CHANGELOG.md)
- [Commits](elixir-ecto/postgrex@v0.15.5...v0.15.6)

Signed-off-by: dependabot[bot] <[email protected]>

mix.lock

@@ -8,7 +8,7 @@
   "cowlib": {:hex, :cowlib, "2.9.1", "61a6c7c50cf07fdd24b2f45b89500bb93b6686579b069a89f88cb211e1125c78", [:rebar3], [], "hexpm", "e4175dc240a70d996156160891e1c62238ede1729e45740bdd38064dad476170"},
   "csv": {:hex, :csv, "2.4.1", "50e32749953b6bf9818dbfed81cf1190e38cdf24f95891303108087486c5925e", [:mix], [{:parallel_stream, "~> 1.0.4", [hex: :parallel_stream, repo: "hexpm", optional: false]}], "hexpm", "54508938ac67e27966b10ef49606e3ad5995d665d7fc2688efb3eab1307c9079"},
   "db_connection": {:hex, :db_connection, "2.2.2", "3bbca41b199e1598245b716248964926303b5d4609ff065125ce98bcd368939e", [:mix], [{:connection, "~> 1.0.2", [hex: :connection, repo: "hexpm", optional: false]}], "hexpm", "642af240d8a8affb93b4ba5a6fcd2bbcbdc327e1a524b825d383711536f8070c"},
-  "decimal": {:hex, :decimal, "1.9.0", "83e8daf59631d632b171faabafb4a9f4242c514b0a06ba3df493951c08f64d07", [:mix], [], "hexpm", "b1f2343568eed6928f3e751cf2dffde95bfaa19dd95d09e8a9ea92ccfd6f7d85"},
+  "decimal": {:hex, :decimal, "2.0.0", "a78296e617b0f5dd4c6caf57c714431347912ffb1d0842e998e9792b5642d697", [:mix], [], "hexpm", "34666e9c55dea81013e77d9d87370fe6cb6291d1ef32f46a1600230b1d44f577"},
   "ecto": {:hex, :ecto, "3.4.6", "08f7afad3257d6eb8613309af31037e16c36808dfda5a3cd0cb4e9738db030e4", [:mix], [{:decimal, "~> 1.6 or ~> 2.0", [hex: :decimal, repo: "hexpm", optional: false]}, {:jason, "~> 1.0", [hex: :jason, repo: "hexpm", optional: true]}, {:telemetry, "~> 0.4", [hex: :telemetry, repo: "hexpm", optional: false]}], "hexpm", "6f13a9e2a62e75c2dcfc7207bfc65645ab387af8360db4c89fee8b5a4bf3f70b"},
   "ecto_enum": {:hex, :ecto_enum, "1.4.0", "d14b00e04b974afc69c251632d1e49594d899067ee2b376277efd8233027aec8", [:mix], [{:ecto, ">= 3.0.0", [hex: :ecto, repo: "hexpm", optional: false]}, {:ecto_sql, "> 3.0.0", [hex: :ecto_sql, repo: "hexpm", optional: false]}, {:mariaex, ">= 0.0.0", [hex: :mariaex, repo: "hexpm", optional: true]}, {:postgrex, ">= 0.0.0", [hex: :postgrex, repo: "hexpm", optional: true]}], "hexpm", "8fb55c087181c2b15eee406519dc22578fa60dd82c088be376d0010172764ee4"},
   "ecto_sql": {:hex, :ecto_sql, "3.4.5", "30161f81b167d561a9a2df4329c10ae05ff36eca7ccc84628f2c8b9fa1e43323", [:mix], [{:db_connection, "~> 2.2", [hex: :db_connection, repo: "hexpm", optional: false]}, {:ecto, "~> 3.4.3", [hex: :ecto, repo: "hexpm", optional: false]}, {:myxql, "~> 0.3.0 or ~> 0.4.0", [hex: :myxql, repo: "hexpm", optional: true]}, {:postgrex, "~> 0.15.0", [hex: :postgrex, repo: "hexpm", optional: true]}, {:tds, "~> 2.1.0", [hex: :tds, repo: "hexpm", optional: true]}, {:telemetry, "~> 0.4.0", [hex: :telemetry, repo: "hexpm", optional: false]}], "hexpm", "31990c6a3579b36a3c0841d34a94c275e727de8b84f58509da5f1b2032c98ac2"},
@@ -43,7 +43,7 @@
   "plug": {:hex, :plug, "1.10.4", "41eba7d1a2d671faaf531fa867645bd5a3dce0957d8e2a3f398ccff7d2ef017f", [:mix], [{:mime, "~> 1.0", [hex: :mime, repo: "hexpm", optional: false]}, {:plug_crypto, "~> 1.1.1 or ~> 1.2", [hex: :plug_crypto, repo: "hexpm", optional: false]}, {:telemetry, "~> 0.4", [hex: :telemetry, repo: "hexpm", optional: false]}], "hexpm", "ad1e233fe73d2eec56616568d260777b67f53148a999dc2d048f4eb9778fe4a0"},
   "plug_cowboy": {:hex, :plug_cowboy, "2.3.0", "149a50e05cb73c12aad6506a371cd75750c0b19a32f81866e1a323dda9e0e99d", [:mix], [{:cowboy, "~> 2.7", [hex: :cowboy, repo: "hexpm", optional: false]}, {:plug, "~> 1.7", [hex: :plug, repo: "hexpm", optional: false]}, {:telemetry, "~> 0.4", [hex: :telemetry, repo: "hexpm", optional: false]}], "hexpm", "bc595a1870cef13f9c1e03df56d96804db7f702175e4ccacdb8fc75c02a7b97e"},
   "plug_crypto": {:hex, :plug_crypto, "1.1.2", "bdd187572cc26dbd95b87136290425f2b580a116d3fb1f564216918c9730d227", [:mix], [], "hexpm", "6b8b608f895b6ffcfad49c37c7883e8df98ae19c6a28113b02aa1e9c5b22d6b5"},
-  "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"},
+  "postgrex": {:hex, :postgrex, "0.15.6", "a464c72010a56e3214fe2b99c1a76faab4c2bb0255cabdef30dea763a3569aa2", [:mix], [{:connection, "~> 1.0", [hex: :connection, repo: "hexpm", optional: false]}, {:db_connection, "~> 2.1", [hex: :db_connection, repo: "hexpm", optional: false]}, {:decimal, "~> 1.5 or ~> 2.0", [hex: :decimal, repo: "hexpm", optional: false]}, {:jason, "~> 1.0", [hex: :jason, repo: "hexpm", optional: true]}], "hexpm", "f99268325ac8f66ffd6c4964faab9e70fbf721234ab2ad238c00f9530b8cdd55"},
   "ranch": {:hex, :ranch, "1.7.1", "6b1fab51b49196860b733a49c07604465a47bdb78aa10c1c16a3d199f7f8c881", [:rebar3], [], "hexpm", "451d8527787df716d99dc36162fca05934915db0b6141bbdac2ea8d3c7afc7d7"},
   "srtm": {:hex, :srtm, "0.5.1", "042c33dff1ba3824f371a6813335062597861617cf951532e8b7343137cb294d", [:mix], [{:castore, "~> 0.1", [hex: :castore, repo: "hexpm", optional: false]}, {:jason, "~> 1.1", [hex: :jason, repo: "hexpm", optional: false]}, {:mint, "~> 1.0", [hex: :mint, repo: "hexpm", optional: false]}, {:tesla, "~> 1.3", [hex: :tesla, repo: "hexpm", optional: false]}], "hexpm", "6be647847b1070a1294f3a59c4de75a9e07159f393479e36e76e09e593dacd28"},
   "ssl_verify_fun": {:hex, :ssl_verify_fun, "1.1.6", "cf344f5692c82d2cd7554f5ec8fd961548d4fd09e7d22f5b62482e5aeaebd4b0", [:make, :mix, :rebar3], [], "hexpm", "bdb0d2471f453c88ff3908e7686f86f9be327d065cc1ec16fa4540197ea04680"},