Update dependencies and Node versions

Author: DABH

.travis.yml

@@ -1,5 +1,5 @@
 language: node_js
 node_js:
+  - "14"
   - "12"
   - "10"
-  - "8"

package.json

@@ -48,10 +48,10 @@
     "is-primitive": "^3.0.1"
   },
   "devDependencies": {
-    "@types/jest": "^25.2.3",
-    "@types/node": "^14.0.11",
-    "jest": "^26.0.1",
-    "ts-jest": "^26.1.0",
-    "typescript": "^3.9.5"
+    "@types/jest": "^26.0.20",
+    "@types/node": "^14.14.31",
+    "jest": "^26.6.3",
+    "ts-jest": "^26.5.2",
+    "typescript": "^4.2.2"
   }
 }