fix: Move `mocha-chai-jest-snapshot` to be a dev dependency

[csandman]

This is a small fix for an issue I've been having for a while installing this package as a dev dependency of my team's app. Every time I do a yarn install in my project, I get a warning about a missing peer dependency of one of this package's dependencies, mocha-chai-jest-snapshot. The fact that this is even considered a dependency and not a dev dependency doesn't really make sense, as it's just a testing library, and all packages that only have to do with testing should not be in the normal dependencies.

So this PR just moves it from being a dependency to a dev dependency. I thought about making an issue for this, but the fix was so straightforward, I figured I'd jus put up a PR instead. Let me know if this works for you!

Here's the actual warning by the way:

warning "@devcycle/cli > [email protected]" has unmet peer dependency "chai@^4.3.6".

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To be honest, there are probably a few more packages that should be moved to dev dependencies. Anything that isn't required for the end user to use the package should be in dev dependencies instead of normal dependencies. Otherwise, that's just extra work for the end user's package manager to reconcile package versions for packages they don't even need. For example, I can't imagine why you'd need @babel/parser in a final version. Any package that is only used during build steps should be in dev dependencies.