Remove side-effects property in package.json (#135)

As it does not have a purpose when there's no imports and only a single default export.

Author: stipsan

package.json

@@ -119,6 +119,5 @@
       "@semantic-release/npm"
     ]
   },
-  "sideEffects": false,
   "typings": "typings/index.d.ts"
 }