Feature/ci conda flux

[RamonAra209]

• Added flux-core and flux-sched to requirements.
• Added flux related tests
• Removed swift-t from requirements and tests due to dependency conflict

[j-woz]

What is the dependency conflict?

[RamonAra209]

@j-woz

Swift-t requires python version3.6 >= python < 3.7

Flux-core and flux-sched need version >= 3.8

[mtitov]

@j-woz is it ok to resolve it outside of this PR?