Ensure team is getting app-level error notification alerts

[GUI]

When an application or code-level error occurs on our api.data.gov systems, it currently gets logged and sent to Rollbar for tracking and alerting purposes. However, it's currently getting logged in a Rollbar account that belongs to NREL, which obviously isn't ideal for api.data.gov. This also means that I'm currently the only one getting these notifications for application-level errors (this is how I found out about #266). These type of errors aren't very frequent (knock on wood), so I had sort of forgotten about this when I was transferring all the ops accounts over to 18F proper, but this would also be a good thing to sort out and make sure everyone on the api.data.gov team has access to.

As a short-term fix, what I think might be easiest is to setup a free Rollbar account for api.data.gov and switch things to point there (our volume should be fine for the free account). As a longer-term fix, switching all of this over to New Relic (which provides similar functionality), would probably make most sense since we're already using New Relic for the servers. However, setting up New Relic will require just a tad more work to get all the proper integrations in place for alerting, so that's why a temporary Rollbar account might be the quickest initial option (since the integrations are already in place in the apps).