Improve testing for 1.0.0

[hategan]

This is a parent task for:

• Expand range of sites used for testing #112
• Use ECP CI #113
• Expand tests to exercise complete range of scheduler options #114
• Add coverage to tests #115

[mturilli]

Probably we want to converge before release.

[hategan]

I renamed this issue from "Improve testing for 0.1.0" to "Improve testing for 1.0.0" since we have reached the desired level of improvement for 0.1.0, but more improvement is possible and should be done for 1.0.0.