patch dependencies and fix imports

[slumber]

Description

Needed for arkworks-rs/r1cs-std#124

arkworks-rs/algebra#577 broke dependencies in some of arkworks crates.
Specifically, arkworks-rs/r1cs-std#124 requires running tests against
all curves but it doesn't compile. This PR won't compile either because there's a cycle-dependency with r1cs-std.

But merging one would unblock another.

---

Before we can merge this PR, please make sure that all the following items have been
checked off. If any of the checklist items are not applicable, please leave them but
write a little note why.

• Targeted PR against correct branch (master)
• Linked to Github issue with discussion and accepted design OR have an explanation in the PR that describes this work.
• Wrote unit tests
• Updated relevant documentation in the code
• Added a relevant changelog entry to the Pending section in CHANGELOG.md
• Re-reviewed Files changed in the Github PR explorer

[slumber]

Not relevant because of #159 I guess

[weikengchen]

Yes, this would be subsumed by that PR. Shall we close this one?

Another PR should do the work.

[weikengchen]

Actually we may still need this PR. We are merging some other PRs and will be back to review this one.