chore(package): remove Greenkeeper section

package.json

@@ -40,25 +40,6 @@
   "files": [
     "src"
   ],
-  "greenkeeper": {
-    "commitMessages": {
-      "initialBadge": "docs(greenkeeper): Add Greenkeeper badge.",
-      "initialDependencies": "chore(greenkeeper): Update dependencies.",
-      "initialBranches": "chore(greenkeeper): Whitelist greenkeeper branches.",
-      "dependencyUpdate": "chore(greenkeeper): ${dependency}@${version}.",
-      "devDependencyUpdate": "chore(greenkeeper): ${dependency}@${version}.",
-      "dependencyPin": "fix(greenkeeper): Pin ${dependency}@${oldVersion}.",
-      "devDependencyPin": "fix(greenkeeper): Pin ${dependency}@${oldVersion}."
-    },
-    "prTitles": {
-      "initialPR": "chore(greenkeeper): Update dependencies and enable Greenkeeper",
-      "initialPrBadge": "docs(greenkeeper): Add Greenkeeper badge and enable Greenkeeper",
-      "initialPrBadgeOnly": "docs(greenkeeper): Add Greenkeeper badge",
-      "initialSubgroupPR": "chore(greenkeeper): Update dependencies for ${group}",
-      "basicPR": "chore(greenkeeper): Update ${dependency}",
-      "groupPR": "chore(greenkeeper): Update ${dependency} for ${group}"
-    }
-  },
   "keywords": [
     "android",
     "asset",