Update to Zenodo citation

Author: Chris Erdmann

Diff for: CITATION

@@ -1,5 +1,5 @@
 Please cite as:
 
-Library Carpentry:
-"Git Intro for Librarians."
-June 2016, https://librarycarpentry.github.io/lc-git/.
+Silvia di Giorgio (Ed.), Christopher Erdmann (Ed.), Thea Atwood (Ed.), Eric Lopatin (Ed.), Drew Heles (Ed.), Eva Seidlmayer (Ed.), Katrin Leinweber (Ed.), Belinda Weaver (Ed.), Jez Cope (Ed.), James Baker, Nora McGregor, Dan Michael O. Heggø, … Wolmar Nyberg Åkerström. (2019, July). LibraryCarpentry/lc-git: Library Carpentry: Introduction to Git, June 2019 (Version v2019.06.1). Zenodo. http://doi.org/10.5281/zenodo.3265772
+
+[![DOI](https://zenodo.org/badge/DOI/10.5281/zenodo.3265772.svg)](https://doi.org/10.5281/zenodo.3265772)