Update to Zenodo citation

Author: Chris Erdmann

CITATION

@@ -1,3 +1,6 @@
 Please cite as:
 
-Library Carpentry: OpenRefine. June 2016. https://librarycarpentry.org/lc-open-refine.
+Erin Carillo (Ed.), Owen Stephens (Ed.), Juliane Schneider (Ed.), Paul R. Pival (Ed.), Kristin Lee (Ed.), Carmi Cronje (Ed.), James Baker, Christopher Erdmann, Tim Dennis, mhidas, Daniel Bangert, Evan Williamson, … Jeffrey Oliver. (2019, July). LibraryCarpentry/lc-open-refine: Library Carpentry: OpenRefine, June 2019 (Version v2019.06.1). Zenodo. http://doi.org/10.5281/zenodo.3266144
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+[![DOI](https://zenodo.org/badge/DOI/10.5281/zenodo.3266144.svg)](https://doi.org/10.5281/zenodo.3266144)
+