Sign assemblies

[sebastienros]

Fixes #481

At least to show what it would mean to have the assemblies signed. I created an .snk file. There is a warning since the Tests reference a non-signed assembly, which could use the same key (it can be reused as much as you want, nothing private to rely on in these).

[CLAassistant]

Thank you for your submission! We really appreciate it. Like many open source projects, we ask that you sign our Contributor License Agreement before we can accept your contribution.
_{You have signed the CLA already but the status is still pending? Let us recheck it.}

[phil-scott-78]

Good news and bad news.

1. I'm gonna close this PR.
2. The good news is that we are going to work on getting a seperate project released that is signed. Once we it is in place, I'll ping @sebastienros so you can check it out as a reviewer.

[lucaspimentel]

I'm gonna close this PR... a seperate project released that is signed

Any reason why you're not signing this project?

[KirillOsenkov]

This PR would unblock a lot of people and it doesn't make anything worse. @patriksvensson