Revert to snapshot publishing following release (#546)

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

Author: bestbeforetoday

package.json

@@ -1,7 +1,7 @@
 {
   "name": "fabric-sdk-node",
-  "version": "1.4.19",
-  "tag": "latest-1.4",
+  "version": "1.4.20-snapshot",
+  "tag": "unstable-1.4",
   "main": "index.js",
   "repository": {
     "type": "git",