chore(package): update dependencies

package.json

@@ -38,16 +38,16 @@
   "homepage": "https://github.com/lukechilds/merge-images",
   "dependencies": {},
   "devDependencies": {
-    "ava": "^0.18.1",
+    "ava": "^0.19.1",
     "camelcase": "^4.0.0",
     "canvas": "^1.6.2",
     "coveralls": "^2.11.15",
     "datauri": "^1.0.5",
     "eslint-config-xo-lukechilds": "^1.0.0",
-    "nyc": "^10.0.0",
-    "pify": "^2.3.0",
-    "rollup": "^0.41.4",
+    "nyc": "^11.0.2",
+    "pify": "^3.0.0",
+    "rollup": "^0.42.0",
     "rollup-plugin-buble": "^0.15.0",
-    "xo": "^0.17.1"
+    "xo": "^0.18.2"
   }
 }