Add `cypress init` command to seed / scaffold test files on current directory

[brian-mann]

We no longer seed anything when running cypress run on a fresh project.

Instead we now error: #618

For that reason we should give users the ability to seed / scaffold out files from the command line instead of using the GUI.

Proposal add a cypress init command which does this.

Bonus points if we offer an inquirer view enabling the user to select what they want to. We could even explain what each one does.

[Knaledge]

@brian-mann - I am running into this exact (exact) situation right now. I am so glad I found this specific issue entry here! It captures exactly what I'm running into.

Is there any ETA?

We do not have the desire to gen node_modules per project (at the moment, or even short term) as we will only be utilizing a single version of Node.js and Cypress for the foreseeable future - and technically don't have a "node" project to even work with atm ;)

Just getting this working (and I have, via desktop) with our current project - so that we can make the case for using it with our next (and quickly approaching) project that will use node.

Or maybe that logic is misapplied. Either way - we went from a "global" installation to a "local" installlation (Cypress CLI was complaining that the .cache folder did not contain a "Cypress" instance) and it worked great.

We now do this:

su - cypress -c 'npm install cypress'

I then do the following, and encounter the "cypress.json" error mentioned here in this issue:

`[cypress@proto ~]$ npx cypress run --spec '/home/cypress/cy.tests/EXAMPLE.staff_login.js'
It looks like this is your first time using Cypress: 3.0.2

✔ Verified Cypress! /home/cypress/.cache/Cypress/3.0.2/Cypress

Opening Cypress...
Could not find any tests to run.

We looked but did not find a cypress.json file in this folder: /home/cypress`

Passing --config (despite no test/spec specified) further underscores this:

`[cypress@proto ~]$ npx cypress run --config integrationFolder=/home/cypress/cy.tests/,fixturesFolder=false
Could not find any tests to run.

We looked but did not find a cypress.json file in this folder: /home/cypress`

[Knaledge]

@brian-mann - Alternatively, just some clear instruction/guidance on how to do this "init" on my own would be so, so helpful as I believe it is the last barricade. Cypress docs - while super awesome (really!) - don't seem to cover what exactly is required for a run to work. It seems there is a lot of reliance on using the UI to select a project (which then generates the required files/folders/etc.) - but as you raised here, we're using CLI entirely.

Even just a few quick pointers to get me on my feet would be incredibly appreciated.