#55 Add support to run only one step or a subset of steps passes as args

[RiyaJohn]

• [x] Does all of your new or changed code have unit tests?
• [x] Is overall unit test statement coverage still above 85%?
• [x] Is code style linting passing with npm run lint?
• [ ] Is the related GitHub issue number included in your branch name? ex branch name: fix/12-some-bug
• [x] Is the related GitHub issue number included in your pull request title? example PR title: "12 - Fixes some bug"
• [ ] Is documentation still up to date after your change?

[RiyaJohn]

Fixes #55

[RiyaJohn]

@worldjoe Can you please review this PR

[RiyaJohn]

@efrancis-intuit @hipstersmoothie Can one of you take a look at it