Update versions following release (#677)

Signed-off-by: Mark S. Lewis <[email protected]>

Author: bestbeforetoday

package.json

@@ -1,7 +1,7 @@
 {
   "name": "fabric-sdk-node",
-  "version": "2.2.18",
-  "tag": "latest",
+  "version": "2.2.19-snapshot",
+  "tag": "unstable",
   "main": "index.js",
   "private": true,
   "repository": {