Add unshielded ownable

[andrew-fleming]

Fixes #39.

PR Checklist

• Tests
• Documentation

This PR proposes to implement a basic Ownable module implementation which is easier for prototyping and early development. This also separates regular ownership transfers and unsafe ownership transfers (to contract addresses). If accepted, we should also include a two-step variant for more secure development

[emnul]

Very nice! Not a whole lot to add on to this given how straightforward the implementation is

[andrew-fleming]

Very nice! Not a whole lot to add on to this given how straightforward the implementation is

Thank you for the review @emnul!

I left a comment on your comment above. I was also thinking it might be better to change the package/dir name to access i.e. contracts/access. The idea being that we can have Ownable and Access Control under the same directory. LMK what you think

(sorry for not doing this earlier in this PR, it just came to mind with the forthcoming change to contracts/token)

[emnul]

I was also thinking it might be better to change the package/dir name to access i.e. contracts/access. The idea being that we can have Ownable and Access Control under the same directory. LMK what you think

Makes sense! Especially since we will be adding even more access modules in the very near term