Update dependencies.

package.json

@@ -15,11 +15,11 @@
     "Christoph Dorn <christoph@christophdorn.com>"
   ],
   "devDependencies": {
-    "browserify": "^16.1.0",
+    "browserify": "^16.5.2",
     "commander": "^2.20.0",
     "cross-env": "^5.2.1",
-    "eslint": "^5.16.0",
-    "eslint-config-digitalbazaar": "^2.2.0",
+    "eslint": "^7.8.1",
+    "eslint-config-digitalbazaar": "^2.5.0",
     "express": "^4.16.2",
     "karma": "^4.4.1",
     "karma-browserify": "^7.0.0",
@@ -31,16 +31,16 @@
     "karma-mocha-reporter": "^2.2.5",
     "karma-safari-launcher": "^1.0.0",
     "karma-sauce-launcher": "^2.0.2",
-    "karma-sourcemap-loader": "^0.3.7",
+    "karma-sourcemap-loader": "^0.3.8",
     "karma-tap-reporter": "0.0.6",
     "karma-webpack": "^4.0.2",
     "mocha": "^5.2.0",
     "mocha-lcov-reporter": "^1.2.0",
     "nodejs-websocket": "^1.7.1",
-    "nyc": "^15.0.0",
+    "nyc": "^15.1.0",
     "opts": "^1.2.7",
-    "webpack": "^4.41.6",
-    "webpack-cli": "^3.3.11",
+    "webpack": "^4.44.1",
+    "webpack-cli": "^3.3.12",
     "worker-loader": "^2.0.0"
   },
   "repository": {