Query#create with has props may interpret values as props

[subvertallchris]

In the other gem, ActiveRel has the ability to gradually assemble a Cypher query that will create a rel and one or both nodes in a single call. This is done using the Query API. While working on importing data at work, I came across a weird bug: an artist whose name is wrapped in curly brackets was being treated as a param. As it happened, this artist's name also had a character in it that would lead to an invalid param, so my call blew up.

I wrote a failing spec in the other gem but I'm not sure that the issue belongs there, so I'm gonna start here. You can see the spec here.

My workaround where ActiveRel is concerned will probably be to just change the factory to use set. Alternatively, I can build my own create String and specify one param for the entire hash but I worry it's too brittle.

As for Query#create, I think that the rule should be that String values given to hashes should always be converted into params. This seems to be where it's happening now.