chore: drop node 4 and update deps

Signed-off-by: Taranveer Virk <taranveer@virk.cc>

.npmrc

@@ -0,0 +1 @@
+package-lock=false

.travis.yml

@@ -1,6 +1,6 @@
 sudo: false
 language: node_js
 node_js:
-  - "4"
   - "6"
   - "8"
+  - "10"

package.json

@@ -15,7 +15,7 @@
     "lint": "eslint ."
   },
   "engines": {
-    "node": ">=4.0.0"
+    "node": ">=6"
   },
   "repository": {
     "type": "git",
@@ -32,20 +32,20 @@
   "homepage": "http://loopback.io",
   "dependencies": {
     "eslint": "^4.13.0",
-    "eslint-config-loopback": "^8.0.0",
+    "eslint-config-loopback": "^10.0.0",
     "loopback-datasource-juggler": "^3.0.0",
     "strong-remoting": "^3.0.0"
   },
   "devDependencies": {
-    "assert": "^1.1.2",
+    "assert": "^1.4.1",
-    "bluebird": "^3.3.5",
+    "bluebird": "^3.5.1",
-    "grunt": "^1.0.1",
+    "grunt": "^1.0.3",
     "grunt-cli": "^1.2.0",
-    "grunt-mocha-test": "^0.12.7",
+    "grunt-mocha-test": "^0.13.3",
     "loopback": "^3.0.0",
-    "mocha": "^3.0.2",
+    "mocha": "^5.2.0",
-    "sinon": "^4.1.3",
+    "sinon": "^6.0.0",
-    "strong-task-emitter": "^0.0.7"
+    "strong-task-emitter": "^0.0.8"
   },
   "optionalDependencies": {}
 }