bblimke/webmock — pull request #427 by dapplebeforedawn (2014-10-26 22:31:16+00:00)
Title: Error on invalid body

It's pretty common for me to try to give a `Hash` to `#to_return(body: )`. This results in errors like:

```ruby
JSON::ParserError:
757: unexpected token at '{:one=>"two"}'
```

It would save debugging time if WebMock raised an error, instead of accepting the Hash. This PR implements that error.