Add a timestamp for builds in the Dashboard. And an option to export the build summary data

It will be good to get a timestamp on the builds that are shown in the dashboard. Currently the Bitrise dashboard shows the builds chronologically but does not show a timestamp.

Also, we should have the option to export the summary data shown in the dashboard for recent builds, say 1, 3 and 7 days.

Use case: This information will be very handy for analysing the builds, so we understand when we have busy periods, whether there are performance issues in specific builds, how many builds are being kicked off, and when we should consider upgrading concurrency and / or plan.

Related to this feature request so Im adding it as a point of reference : http://discuss.bitrise.io/t/api-to-retrieve-the-build-summary/

:slight_smile: