Case insensitive tokens

[StevenClontz]

closes #248

[mikker]

I don't think we should do anything at write time. Rather, let's just upcase in SQL when searching for tokens

[StevenClontz]

Suggested change

	def token=(token)
	Passwordless.config.case_insensitive_tokens ? modified_token = token.upcase : modified_token = token
	self.token_digest = Passwordless.digest(modified_token)
	@token = (modified_token)
	def token=(plaintext)
	self.token_digest = Passwordless.digest(plaintext)
	@token = (plaintext)

[StevenClontz]

I think we have to do this at write time - we're persisting the token digest, not the token, so I believe we cannot upcase the token digest when searching for tokens.