Bump prodash to a version not pinned on time =0.2.22

[edward-shen]

This issue was created to track progress on RUSTSEC-2020-0056 and RUSTSEC-2020-0071, which are advisories caused by a dependency on time =0.2.22 (see time-rs/time#293 for more details).

The git-oxide project won't be affected by these advisories until local time support is added.

Requirements to close this issue:

• prodash dependency is bumped to a version not depending on time =0.2.22.
• Exceptions are removed in deny.toml.

[Byron]

This has been fixed in the mean time 🎉.