Allow user to change Mocha timeout

Is your feature request related to a problem? Please describe. Insomnia Designer currently allows multiple requests to be created as part of a single unit test. This is an important functionality if you have multiple requests relying on a previous ones (request chaining helps, but for more complex situations it fails to satisfy the need). The problem is that the Mocha timeout is hard-coded to 5000ms. Which means if you add multiple request to a single unit test, you are almost guaranteed to see and error saying the test failed because "Timeout of 5000ms exceeded". Describe the solution you'd like Ideally, we either need a way to set the Mocha timeout in User Preferences, or some way to set the timeout within the unit test itself (ex. insomnia.mocha.timeout = 60000). Or if that is a lot of work, then least for the short-term, hard-code the timeout to something much larger (ex. 60 seconds). Describe alternatives you've considered Currently we are using po…