Add bower to dev dependencies

[artemisSystem]

Description of the change

Adds bower to the npm dev dependencies, given it's used for retrieving dependencies.

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Checklist:

• Added the change to the changelog's "Unreleased" section with a reference to this PR (e.g. "- Made a change (#0000)")
• [] Linked any existing issues or proposals that this pull request should close
• [] Updated or added relevant documentation

[garyb]

We omit bower from every package.json actually, it's not an oversight. I'm pretty sure at one point that was the recommendation, and to rely on a single globally installed bower, but I might be making that up as I can't find anything saying that now.

I'm going to close this since even if it may be a little unusual it's consistent with all the other libraries, and we could just migrate to spago also as an alternative.