Bump excoveralls from 0.17.1 to 0.18.0

Bumps [excoveralls](https://github.com/parroty/excoveralls) from 0.17.1 to 0.18.0.
- [Release notes](https://github.com/parroty/excoveralls/releases)
- [Changelog](https://github.com/parroty/excoveralls/blob/master/CHANGELOG.md)
- [Commits](parroty/excoveralls@v0.17.1...v0.18.0)

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

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

mix.exs

@@ -41,7 +41,7 @@ defmodule ElixirAuthGoogle.MixProject do
       {:jason, "~> 1.2"},
 
       # Track test coverage: github.com/parroty/excoveralls
-      {:excoveralls, "~> 0.17.0", only: [:test, :dev]},
+      {:excoveralls, "~> 0.18.0", only: [:test, :dev]},
 
       # Mock stuffs in test: github.com/jjh42/mock
       {:mock, "~> 0.3.0", only: :test},

mix.lock

@@ -5,7 +5,7 @@
   "earmark": {:hex, :earmark, "1.4.9", "837e4c1c5302b3135e9955f2bbf52c6c52e950c383983942b68b03909356c0d9", [:mix], [{:earmark_parser, ">= 1.4.9", [hex: :earmark_parser, repo: "hexpm", optional: false]}], "hexpm", "0d72df7d13a3dc8422882bed5263fdec5a773f56f7baeb02379361cb9e5b0d8e"},
   "earmark_parser": {:hex, :earmark_parser, "1.4.37", "2ad73550e27c8946648b06905a57e4d454e4d7229c2dafa72a0348c99d8be5f7", [:mix], [], "hexpm", "6b19783f2802f039806f375610faa22da130b8edc21209d0bff47918bb48360e"},
   "ex_doc": {:hex, :ex_doc, "0.30.7", "dc7247091aec738ab781f71cbebfc07979d1040c98c7ee67dbde99b7829b743d", [:mix], [{:earmark_parser, "~> 1.4.31", [hex: :earmark_parser, repo: "hexpm", optional: false]}, {:makeup_elixir, "~> 0.14", [hex: :makeup_elixir, repo: "hexpm", optional: false]}, {:makeup_erlang, "~> 0.1", [hex: :makeup_erlang, repo: "hexpm", optional: false]}], "hexpm", "868ff1c7a44c462741853840d1e7ef19a07906e7467cb8da070c158ea6a42a51"},
-  "excoveralls": {:hex, :excoveralls, "0.17.1", "83fa7906ef23aa7fc8ad7ee469c357a63b1b3d55dd701ff5b9ce1f72442b2874", [:mix], [{:castore, "~> 1.0", [hex: :castore, repo: "hexpm", optional: true]}, {:jason, "~> 1.0", [hex: :jason, repo: "hexpm", optional: false]}], "hexpm", "95bc6fda953e84c60f14da4a198880336205464e75383ec0f570180567985ae0"},
+  "excoveralls": {:hex, :excoveralls, "0.18.0", "b92497e69465dc51bc37a6422226ee690ab437e4c06877e836f1c18daeb35da9", [:mix], [{:castore, "~> 1.0", [hex: :castore, repo: "hexpm", optional: true]}, {:jason, "~> 1.0", [hex: :jason, repo: "hexpm", optional: false]}], "hexpm", "1109bb911f3cb583401760be49c02cbbd16aed66ea9509fc5479335d284da60b"},
   "file_system": {:hex, :file_system, "0.2.10", "fb082005a9cd1711c05b5248710f8826b02d7d1784e7c3451f9c1231d4fc162d", [:mix], [], "hexpm", "41195edbfb562a593726eda3b3e8b103a309b733ad25f3d642ba49696bf715dc"},
   "hackney": {:hex, :hackney, "1.18.1", "f48bf88f521f2a229fc7bae88cf4f85adc9cd9bcf23b5dc8eb6a1788c662c4f6", [:rebar3], [{:certifi, "~> 2.9.0", [hex: :certifi, repo: "hexpm", optional: false]}, {:idna, "~> 6.1.0", [hex: :idna, repo: "hexpm", optional: false]}, {:metrics, "~> 1.0.0", [hex: :metrics, repo: "hexpm", optional: false]}, {:mimerl, "~> 1.1", [hex: :mimerl, repo: "hexpm", optional: false]}, {:parse_trans, "3.3.1", [hex: :parse_trans, repo: "hexpm", optional: false]}, {:ssl_verify_fun, "~> 1.1.0", [hex: :ssl_verify_fun, repo: "hexpm", optional: false]}, {:unicode_util_compat, "~> 0.7.0", [hex: :unicode_util_compat, repo: "hexpm", optional: false]}], "hexpm", "a4ecdaff44297e9b5894ae499e9a070ea1888c84afdd1fd9b7b2bc384950128e"},
   "httpoison": {:hex, :httpoison, "2.1.0", "655fd9a7b0b95ee3e9a3b535cf7ac8e08ef5229bab187fa86ac4208b122d934b", [:mix], [{:hackney, "~> 1.17", [hex: :hackney, repo: "hexpm", optional: false]}], "hexpm", "fc455cb4306b43827def4f57299b2d5ac8ac331cb23f517e734a4b78210a160c"},