Remove ParametrizedSchedule dependency

[nkanazawa1989]

Summary

Remove dependency on ParametrizedSchedule as per Qiskit/qiskit#6949

Details and comments

[taalexander]

This seems reasonable to me. Is there someone else that should review?

[nkanazawa1989]

I don't think so. We can merge this and remove ParametrizedSchedule from terra.

[mtreinish]

I think the only thing here is that the minimum terra version in the requirements list is 0.13 iirc. I don't think that this pr will work with a terra version that old. Can you bump the minimum required version to the one where this will work?

[nkanazawa1989]

Thanks @mtreinish I realized Ignis doesn't provide requirements file but they are hard-coded in the setup file. The requirements for terra 0.13 is already there.
https://github.com/Qiskit/qiskit-ignis/blob/15c2be1cbc80edb637ce5a80f2c9101adfd8fc44/setup.py#L21-L27

[taalexander]

Is this good to go @mtreinish?

[mtreinish]

Was the pulse builder syntax added in terra 0.13.0? I can't remember and I didn't see it mentioned in the release notes anywhere. If it was then yeah this is good to go. I just thought it was more recent than 0.13.0

[nkanazawa1989]

There was no release note for the builder but this is the first PR Qiskit/qiskit#4174
Seems like terra > 0.15 is necessary?

[nkanazawa1989]

Set terra version 0.15.1 according to https://qiskit.org/documentation/release_notes.html

0.20.0	0.15.1	0.6.1	0.4.0	0.8.0	0.7.5	2020-08-10

Please let me know if I'm wrong.

[mtreinish]

Yep it looks like it was first released in 0.15.0: https://github.com/Qiskit/qiskit-terra/releases/tag/0.15.0 (there was a changelog entry for the PR despite not having a release note :/ ) so setting the minimum to 0.15.x is appropriate