build(deps-dev): Bump excoveralls from 0.18.3 to 0.18.4 (#1225)

Bumps [excoveralls](https://github.com/parroty/excoveralls) from 0.18.3 to 0.18.4.
- [Release notes](https://github.com/parroty/excoveralls/releases)
- [Changelog](https://github.com/parroty/excoveralls/blob/master/CHANGELOG.md)
- [Commits](parroty/excoveralls@v0.18.3...v0.18.4)

---
updated-dependencies:
- dependency-name: excoveralls
  dependency-type: direct:development
  update-type: version-update:semver-patch
...

Signed-off-by: dependabot[bot] <support@github.com>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

mix.lock

@@ -41,7 +41,7 @@
   "ex_rated": {:hex, :ex_rated, "2.1.0", "d40e6fe35097b10222df2db7bb5dd801d57211bac65f29063de5f201c2a6aebc", [:mix], [{:ex2ms, "~> 1.5", [hex: :ex2ms, repo: "hexpm", optional: false]}], "hexpm", "936c155337253ed6474f06d941999dd3a9cf0fe767ec99a59f2d2989dc2cc13f"},
   "ex_utils": {:hex, :ex_utils, "0.1.7", "2c133e0bcdc49a858cf8dacf893308ebc05bc5fba501dc3d2935e65365ec0bf3", [:mix], [], "hexpm", "66d4fe75285948f2d1e69c2a5ddd651c398c813574f8d36a9eef11dc20356ef6"},
   "exactor": {:hex, :exactor, "2.2.4", "5efb4ddeb2c48d9a1d7c9b465a6fffdd82300eb9618ece5d34c3334d5d7245b1", [:mix], [], "hexpm", "1222419f706e01bfa1095aec9acf6421367dcfab798a6f67c54cf784733cd6b5"},
-  "excoveralls": {:hex, :excoveralls, "0.18.3", "bca47a24d69a3179951f51f1db6d3ed63bca9017f476fe520eb78602d45f7756", [:mix], [{:castore, "~> 1.0", [hex: :castore, repo: "hexpm", optional: true]}, {:jason, "~> 1.0", [hex: :jason, repo: "hexpm", optional: false]}], "hexpm", "746f404fcd09d5029f1b211739afb8fb8575d775b21f6a3908e7ce3e640724c6"},
+  "excoveralls": {:hex, :excoveralls, "0.18.4", "70f70dc37b9bd90cf66868c12778d2f60b792b79e9e12aed000972a8046dc093", [:mix], [{:castore, "~> 1.0", [hex: :castore, repo: "hexpm", optional: true]}, {:jason, "~> 1.0", [hex: :jason, repo: "hexpm", optional: false]}], "hexpm", "cda8bb587d9deaa0da6158cf0a18929189abbe53bf42b10fe70016d5f4f5d6a9"},
   "exjsx": {:hex, :exjsx, "4.0.0", "60548841e0212df401e38e63c0078ec57b33e7ea49b032c796ccad8cde794b5c", [:mix], [{:jsx, "~> 2.8.0", [hex: :jsx, repo: "hexpm", optional: false]}], "hexpm", "32e95820a97cffea67830e91514a2ad53b888850442d6d395f53a1ac60c82e07"},
   "expo": {:hex, :expo, "0.4.1", "1c61d18a5df197dfda38861673d392e642649a9cef7694d2f97a587b2cfb319b", [:mix], [], "hexpm", "2ff7ba7a798c8c543c12550fa0e2cbc81b95d4974c65855d8d15ba7b37a1ce47"},
   "exvcr": {:hex, :exvcr, "0.15.2", "2216c8605b5c3e300160c2a5bd896b4928fa51fc3fb3420d3e792ad833ac89ba", [:mix], [{:exactor, "~> 2.2", [hex: :exactor, repo: "hexpm", optional: false]}, {:exjsx, "~> 4.0", [hex: :exjsx, repo: "hexpm", optional: false]}, {:finch, "~> 0.16", [hex: :finch, repo: "hexpm", optional: true]}, {:httpoison, "~> 1.0 or ~> 2.0", [hex: :httpoison, repo: "hexpm", optional: true]}, {:httpotion, "~> 3.1", [hex: :httpotion, repo: "hexpm", optional: true]}, {:ibrowse, "4.4.0", [hex: :ibrowse, repo: "hexpm", optional: true]}, {:meck, "~> 0.8", [hex: :meck, repo: "hexpm", optional: false]}], "hexpm", "2bd4125889bd3953d7fbb7b388c34190c31e292f12896da56ecf0743d40439ed"},