... from multiple datastreams. Its single parameter is an array of
strings representing the building, sensor and sampling rate.

Retrieves metadata from an array of Datastream URL strings

Add parameters to function that hold information about the two series.

Remove hardcoded arrays used for testing.

Returns the abbreviated versions of building IDs, phenomenon names
and sensor sampling rates

Returns the values of the currently selected options in the linked
drop down lists

... based on the selection in first dropdown list. Functionality based
on a new `hidden` CSS class

Create parent `<div>` elements for both dropdown lists. In addition,
attach a barebones event listener to the new dropdown list