Feature request: Run subset of single spec file from CLI

[gone]

Current behavior:

Currently when running a single spec file all tests within the spec file are run. I'm scripting the test run within a larger app and I'm trying to do a flow of set up -> run cypress -> check data -> tear down around the test and currently I can't isolate each test to check the results.

Desired behavior:

I'd like to be able to run a subset (one) similar to how mocha's -g flag works https://mochajs.org/#-grep-regexp-g-regexp

something like
yarn run cypress run --spec "src/__tests__/cypress/integration/signup.js" -g "it works"
yarn run cypress run --spec "src/__tests__/cypress/integration/signup.js" -g "this one fails"

[jennifer-shehane]

Duplicate of #1865