Merge pull request #19 from bootstrap-styled/greenkeeper/rollup-plugin-terser-4.0.0

Update rollup-plugin-terser to the latest version 🚀

Author: kopax

package.json

@@ -166,7 +166,7 @@
     "rollup-plugin-node-builtins": "^2.1.2",
     "rollup-plugin-node-resolve": "^4.0.0",
     "rollup-plugin-replace": "^2.1.0",
-    "rollup-plugin-terser": "^3.0.0",
+    "rollup-plugin-terser": "^4.0.0",
     "rollup-plugin-visualizer": "^0.9.2",
     "rollup-watch": "^4.3.1",
     "semantic-release": "^15.13.1",