Update previous publish date.

Author: gkellogg

index.html

@@ -24,8 +24,8 @@
 
       // if there is a previously published draft, uncomment this and set its YYYY-MM-DD date
       // and its maturity status
-      prevVersion:          "https://www.w3.org/TR/2019/CR-json-ld11-api-20200305/",
-      previousPublishDate:  "2020-03-05",
+      prevVersion:          "https://www.w3.org/TR/2019/CR-json-ld11-api-20200417/",
+      previousPublishDate:  "2020-04-17",
       previousMaturity:     "CR",
       prevRecURI:           "https://www.w3.org/TR/2014/REC-json-ld-api-20140116/",