chore: update @callstack/eslint-config to the latest version 🚀 (#134)

## The devDependency [@callstack/eslint-config](https://github.com/callstack/eslint-config-callstack) was updated from `3.0.2` to `4.0.0`.
This version is **not covered** by your **current version range**.

If you don’t accept this pull request, your project will work just like it did before. However, you might be missing out on a bunch of new features, fixes and/or performance improvements from the dependency update.

---

[Find out more about this release](https://github.com/callstack/eslint-config-callstack).

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package.json

@@ -12,14 +12,14 @@
     "@babel/cli": "^7.1.2",
     "@babel/core": "^7.1.2",
     "@babel/runtime": "^7.1.2",
-    "@callstack/eslint-config": "^3.0.0",
+    "@callstack/eslint-config": "^4.0.1",
     "@types/react": "^16.7.11",
     "@types/react-test-renderer": "^16.0.3",
     "babel-jest": "^24.1.0",
     "chalk": "^2.4.1",
     "conventional-changelog-cli": "^2.0.11",
     "dedent": "^0.7.0",
-    "eslint": "^5.14.1",
+    "eslint": "^5.15.2",
     "flow-bin": "^0.94.0",
     "flow-copy-source": "^2.0.2",
     "jest": "^24.1.0",