update spike-core to version 0.12.0 (#18)

Author: jescalan

package.json

@@ -23,7 +23,7 @@
     "coveralls": "2.x",
     "nyc": "^8.1.0",
     "source-loader": "^0.2.0",
-    "spike-core": "^0.11.0",
+    "spike-core": "^0.12.0",
     "standard": "^8.0.0"
   },
   "engines": {