Update GOVERNANCE.md (#585)

Updated my affiliation

GOVERNANCE.md

@@ -14,7 +14,7 @@ Current core team members are:
 | Brian O'Connor     | University of California, Santa Cruz | [briandoconnor](https://github.com/briandoconnor) |
 | Geraldine Van der Auwera | Broad Institute | [vdauwera](https://github.com/vdauwera) |
 | Christopher Llanwarne | Broad Institute | [cjllanwarne](https://github.com/cjllanwarne) |
-| John Didion | Apton | [jdidion](https://github.com/jdidion) |
+| John Didion | Fulcrum Genomics | [jdidion](https://github.com/jdidion) |
 | Michael Franklin | Centre for Population Genomics | [illusional](https://github.com/illusional) |
 | Amy Paguirigan | Fred Hutch | [vortexing](https://github.com/vortexing) |
 | Ruben Vorderman | Leiden University Medical Center | [rhpvorderman](https://github.com/rhpvorderman) |