removed unecessary devDependency

package.json

@@ -27,7 +27,6 @@
     "@kadira/storybook": "^2.35.3",
     "@kadira/storybook-deployer": "^1.2.0",
     "@kadira/storyshots": "^2.1.0",
-    "@storybook/addon-storyshots": "^3.0.0",
     "babel-cli": "^6.24.1",
     "babel-loader": "^7.0.0",
     "babel-plugin-transform-object-rest-spread": "^6.23.0",