Merge branch 'master' into unstable

package.json

@@ -28,7 +28,7 @@
   },
   "dependencies": {
     "@chris.troutner/bch-js": "^2.0.0",
-    "apidoc": "^0.20.0",
+    "apidoc": "^0.22.0",
     "axios": "^0.19.0",
     "bitcore-lib-cash": "^8.16.2",
     "body-parser": "^1.18.3",
@@ -47,7 +47,7 @@
     "mkdirp": "^1.0.0",
     "mocha": "^7.1.1",
     "morgan": "^1.9.1",
-    "mqtt": "^3.0.0",
+    "mqtt": "^4.0.0",
     "passport": "^0.4.0",
     "passport-anonymous": "^1.0.1",
     "passport-http": "^0.3.0",