Add Node 11 to CI, experimental only, no prebuild

Hide deprecation warnings - see nodejs/nan#811

package.json

@@ -88,15 +88,16 @@
     "vips"
   ],
   "dependencies": {
+    "bindings": "^1.3.0",
     "color": "^3.1.0",
     "detect-libc": "^1.0.3",
-    "nan": "^2.11.1",
     "fs-copy-file-sync": "^1.1.1",
+    "nan": "^2.11.1",
     "npmlog": "^4.1.2",
     "prebuild-install": "^5.2.1",
     "semver": "^5.6.0",
     "simple-get": "^3.0.3",
-    "tar": "^4.4.6",
+    "tar": "^4.4.8",
     "tunnel-agent": "^0.6.0"
   },
   "devDependencies": {
@@ -109,7 +110,7 @@
     "mocha": "^5.2.0",
     "mock-fs": "^4.7.0",
     "nyc": "^13.1.0",
-    "prebuild": "^8.1.1",
+    "prebuild": "^8.1.2",
     "prebuild-ci": "^2.2.3",
     "rimraf": "^2.6.2",
     "semistandard": "^12.0.1"