ci: test WASM

[realeinherjar]

Since #59 mentioned that wasm would break under certain circumstances, we have no idea when it will break. Hence, this PR adds WASM checks in the CI.

From @LLFourn in #59:

PS are we testing this crate on WASM? If not PR fixing that before this one would be good.

[realeinherjar]

MSRV is broken. I will work on a fix in a new PR and rebase this one.

[coveralls]

Pull Request Test Coverage Report for Build 6645467208

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.

• For more information on this, see Tracking coverage changes with pull request builds.
• To avoid this issue with future PRs, see these Recommended CI Configurations.
• For a quick fix, rebase this PR at GitHub. Your next report should be accurate.

Details

• 0 of 0 changed or added relevant lines in 0 files are covered.
• 1 unchanged line in 1 file lost coverage.
• Overall coverage decreased (-0.03%) to 79.283%

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Files with Coverage Reduction	New Missed Lines	%
src/api.rs	1	28.99%
<!--	Total:	1		-->

Totals
Change from base Build 6407211107:	-0.03%
Covered Lines:	907
Relevant Lines:	1144

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💛 - Coveralls