Added Journal of Magnetic Resonance Imaging to styles.

Created new style for the Journal of Magnetic Resonance Imaging. Could not find exactly this style anywhere in the current list.
And the original validation error was because

`<link href="http://onlinelibrary.wiley.com/journal/10.1002/(ISSN)1522-2586/homepage/ForAuthors.html"/>`

didn't have the "rel" attribute. See http://validator.citationstyles.org/?url=https%3A%2F%2Fraw.githubusercontent.com%2Fwouterpotters%2Fstyles%2F4f9d010366d948bc82e19eaf198df3fde2c7a096%2Fjournal-of-magnetic-resonance-imaging.csl&version=1.0.1