Bump ex_keccak from 0.7.6 to 0.7.8 (#219)

Author: dependabot[bot]

mix.lock

@@ -8,7 +8,7 @@
   "ethereumex": {:hex, :ethereumex, "0.12.1", "20b6b14dd92ef6f09246c643c2385e5c18fda35595b8b8acd05d28cdffff4247", [:make, :mix], [{:finch, "~> 0.16", [hex: :finch, repo: "hexpm", optional: false]}, {:jason, "~> 1.4", [hex: :jason, repo: "hexpm", optional: true]}, {:poolboy, "~> 1.5", [hex: :poolboy, repo: "hexpm", optional: false]}, {:telemetry, "~> 0.4 or ~> 1.0", [hex: :telemetry, repo: "hexpm", optional: false]}, {:websockex, "~> 0.4.3", [hex: :websockex, repo: "hexpm", optional: false]}], "hexpm", "6a7a5610f80f53384499b4f59549b84e9b9d0d15c844889ca0fedc385b891b4e"},
   "ex_abi": {:hex, :ex_abi, "0.8.3", "e01cbafd81008db9e8bc8ac0a4ae5bf08e86a2d82afdca242550269445b80e04", [:mix], [{:ex_keccak, "~> 0.7.6", [hex: :ex_keccak, repo: "hexpm", optional: true]}], "hexpm", "6349a10331c54a1e09865811f705913fa181bc75b4c9a2d326fd96e21bf60cd4"},
   "ex_doc": {:hex, :ex_doc, "0.38.2", "504d25eef296b4dec3b8e33e810bc8b5344d565998cd83914ffe1b8503737c02", [:mix], [{:earmark_parser, "~> 1.4.44", [hex: :earmark_parser, repo: "hexpm", optional: false]}, {:makeup_c, ">= 0.1.0", [hex: :makeup_c, repo: "hexpm", optional: true]}, {:makeup_elixir, "~> 0.14 or ~> 1.0", [hex: :makeup_elixir, repo: "hexpm", optional: false]}, {:makeup_erlang, "~> 0.1 or ~> 1.0", [hex: :makeup_erlang, repo: "hexpm", optional: false]}, {:makeup_html, ">= 0.1.0", [hex: :makeup_html, repo: "hexpm", optional: true]}], "hexpm", "732f2d972e42c116a70802f9898c51b54916e542cc50968ac6980512ec90f42b"},
-  "ex_keccak": {:hex, :ex_keccak, "0.7.6", "110c3ed76b55265975d9ae6628205b8a026f11fe081f3073e00c29aab2e91473", [:mix], [{:rustler, ">= 0.0.0", [hex: :rustler, repo: "hexpm", optional: true]}, {:rustler_precompiled, "~> 0.8", [hex: :rustler_precompiled, repo: "hexpm", optional: false]}], "hexpm", "9d1568424eb7b995e480d1b7f0c1e914226ee625496600abb922bba6f5cdc5e4"},
+  "ex_keccak": {:hex, :ex_keccak, "0.7.8", "be1cf194d3158f0a305eaed0334e478d0d0f2c827e7c1f8f0e1e2a667da5a8ac", [:mix], [{:rustler, ">= 0.0.0", [hex: :rustler, repo: "hexpm", optional: true]}, {:rustler_precompiled, "~> 0.8", [hex: :rustler_precompiled, repo: "hexpm", optional: false]}], "hexpm", "52de5b42b718df2534fb9a55780d8a05bbaea539f867c3e7c0a8e7e1d5f149d9"},
   "ex_rlp": {:hex, :ex_rlp, "0.6.0", "985391d2356a7cb8712a4a9a2deb93f19f2fbca0323f5c1203fcaf64d077e31e", [:mix], [], "hexpm", "7135db93b861d9e76821039b60b00a6a22d2c4e751bf8c444bffe7a042f1abaf"},
   "ex_secp256k1": {:hex, :ex_secp256k1, "0.7.6", "49ea3b07dbc55e2b339e2cd54c6fcb3434620e2de1dfbb4b4f41351384119579", [:mix], [{:rustler, ">= 0.0.0", [hex: :rustler, repo: "hexpm", optional: true]}, {:rustler_precompiled, "~> 0.8", [hex: :rustler_precompiled, repo: "hexpm", optional: false]}], "hexpm", "b84c9c4d85b47410cd951222b4d2b644cdbff96f4f83bc5ac96ee15d850a113c"},
   "excoveralls": {:hex, :excoveralls, "0.18.5", "e229d0a65982613332ec30f07940038fe451a2e5b29bce2a5022165f0c9b157e", [:mix], [{:castore, "~> 1.0", [hex: :castore, repo: "hexpm", optional: true]}, {:jason, "~> 1.0", [hex: :jason, repo: "hexpm", optional: false]}], "hexpm", "523fe8a15603f86d64852aab2abe8ddbd78e68579c8525ae765facc5eae01562"},