Send/Sync adjustment

[fjarri]

• Remove Send + Sync bound from WireFormat
• Remove Send bound on ProtocolError

Closes #13. Seems like this is as much as we can do. Since Rounds are boxed, we can't add Send + Sync bounds on them in public API signatures. Same goes for Payloads and Artifacts. This only really leaves Protocol's and SessionParameterss associated types. PartyId is left Send + Sync because it is used in Round implementations, and specifying that bound every time would just be too much boilerplate.

[coveralls]

Pull Request Test Coverage Report for Build 13249231959

Warning: This coverage report may be inaccurate.

This pull request's base commit is no longer the HEAD commit of its target branch. This means it includes changes from outside the original pull request, including, potentially, unrelated coverage changes.

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Details

• 1 of 1 (100.0%) changed or added relevant line in 1 file are covered.
• 10 unchanged lines in 1 file lost coverage.
• Overall coverage decreased (-0.02%) to 73.299%

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Files with Coverage Reduction	New Missed Lines	%
manul/src/session/tokio.rs	10	88.05%

Totals
Change from base Build 13248845649:	-0.02%
Covered Lines:	2273
Relevant Lines:	3101

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💛 - Coveralls