Image url doesn't allow for an _IMAGE_NAME_ with '-' or multiple '.'

[SamWyld]

When trying to query an image using this format: https://images.graph.cool/v1/PROJECT_ID/FILE_SECRET/IMAGE_NAME.EXTENSION

If the image name has includes '-' or multiple '.' it will fail and return this error: Error: Invalid resize, crop pattern or name of image: image-name.jpg

[schickling]

Thanks a lot for bringing this up! Would you mind adding a few test cases as a PR which reproduce the problem?

Bonus points for also adding the solution to the PR :)