Upgrade dependencies

[benmccann]

Thank you for opening a Pull Request! Before submitting your PR, there are a few things you can do to make sure it goes smoothly:

• Make sure to open an issue as a bug/issue before writing your code! That way we can discuss the change, evaluate designs, and agree on the general idea
• Ensure the tests and linter pass
• Code coverage does not decrease (if any source code was changed)
• Appropriate docs were updated (if necessary)

This is fixes a number of security issues. It also makes sure we're testing against the latest version of Svelte (#234)

[cannahum]

We are anxious to use svelte-htm but this issue is blocking us. If this indeed is the fix, can we move it along?

[sastan]

Thank you @benmccann This slipped right trough. Sorry for the delay