Upgrade to libvips v8.5.5

package.json

@@ -70,7 +70,7 @@
     "got": "^6.7.1",
     "nan": "^2.6.2",
     "semver": "^5.3.0",
-    "tar": "^2.2.1"
+    "tar": "^3.1.3"
   },
   "devDependencies": {
     "async": "^2.4.0",
@@ -78,7 +78,7 @@
     "documentation": "^4.0.0-rc.1",
     "exif-reader": "^1.0.2",
     "icc": "^1.0.0",
-    "mocha": "^3.3.0",
+    "mocha": "^3.4.1",
     "nyc": "^10.3.2",
     "rimraf": "^2.5.4",
     "semistandard": "^11.0.0",
@@ -86,7 +86,7 @@
   },
   "license": "Apache-2.0",
   "config": {
-    "libvips": "8.5.4"
+    "libvips": "8.5.5"
   },
   "engines": {
     "node": ">=4"