Update underscore.

Author: brendanburns

package-lock.json

@@ -70,7 +70,7 @@
     "tar": "^6.1.11",
     "tmp-promise": "^3.0.2",
     "tslib": "^1.9.3",
-    "underscore": "^1.9.1",
+    "underscore": "^1.13.6",
     "ws": "^7.3.1"
   },
   "devDependencies": {
@@ -81,7 +81,7 @@
     "@types/mock-fs": "^3.6.30",
     "@types/stream-buffers": "^3.0.3",
     "@types/tar": "^4.0.3",
-    "@types/underscore": "^1.8.9",
+    "@types/underscore": "^1.11.4",
     "chai": "^4.2.0",
     "chai-as-promised": "^7.1.1",
     "husky": "^2.3.0",