Must delete all AirNow, non-China US dip facilities data in archive

[RocketD0g]

Because of #279, we must now go back and delete historical data aggregated into our system from AirNow (excluding China US dip facilities).

Before doing so, we need to notify the community on medium, slack, etc, so that anyone who still wants this data can access it before deletion. My current thought is to give two weeks once the announcement is made. Other thoughts welcome.

Note: We currently do not have the capability to add in non-real time data into our system from a government source. Currently all data in our system from government sources has been aggregated in real-time, and we would have no way to differentiate post-processed, QA/QC'ed data with this real-time data. If we do gain this capability, we would be able to back fill in these data again from records on AirNow.

[RocketD0g]

As mentioned in the close out of #279, in the RSS feed mentioned in #279 now reflects the true concentration. This took place on Weds,March 15th. I'm seeking to confirm the exact timestamp that differentiates this change. At minimum: This place was already in place at 2pm EST on March 15, and it is safe to assume that prior to March 15, this change was not in place yet.

[dolugen]

Is this done?

[jflasher]

Not yet, I think we'll need to let people know it's happening and then I can go ahead and delete right from database.

[majesticio]

@russbiggs should we go ahead and delete all non-China AirNow data prior to March 15 2017?