Temporarily remove CLA

[mbland]

Of course after adding a CLA notice in #214 and #215, I see this:

• "Does my project need an additional contributor agreement? Probably not."
• "GitHub Terms of Service: D. User-Generated Content: 6. Contributions Under Repository License"

For the time being, references to https://github.com/mbland/cla should be replaced with these references instead.