Downgrade Cypress version back to non-failing version

We currently have an intermittent failure happening in Travis stemming from yauzl, the unzipping tool used by Cypress. The issue is currently open in their issues and can be found here: https://github.com/cypress-io/cypress/issues/3515

According to some feedback on that linked issue, some have had luck downgrading the version of Cypress to 3.1.0. We should downgrade and test with multiple builds to try to resolve this issue.