Add Linter

[AryanJ-NYC]

Story

As a developer:
I would like to linting rules to be implemented for consistent code style.

Acceptance Criteria

• Lint script should be added to package.json
• Linter should reject code not following lint rules

Open questions

• What linting style should we choose? Airbnb is a popular one.

[cmenedes]

Right now we have eslinter-config-rallycoding set up:

in package.json -

 "devDependencies": {
    "babel-jest": "22.4.1",
    "babel-preset-react-native": "4.0.0",
    "eslint-config-rallycoding": "^3.2.0",
    "jest": "22.4.2",
    "react-test-renderer": "16.2.0"
  }

in .esllintrc -

{
  "extends": "rallycoding",
  "rules": {
    "arrow-body-style": 0
  }
}

Should this config remain in the separate file? Or is it preferred to have the eslintConfig in the package.json?
We can change the style as well if that is what the standard is.

[AryanJ-NYC]

This looks good to me. We'll close this when it makes it into master.

[AryanJ-NYC]

A script to run linter is still needed.