chore(deps-dev): bump rollup from 1.6.0 to 1.6.1

Bumps [rollup](https://github.com/rollup/rollup) from 1.6.0 to 1.6.1.
- [Release notes](https://github.com/rollup/rollup/releases)
- [Changelog](https://github.com/rollup/rollup/blob/master/CHANGELOG.md)
- [Commits](https://github.com/rollup/rollup/compare/v1.6.0...v1.6.1)

Signed-off-by: dependabot[bot] <support@dependabot.com>

web3.js/package-lock.json

@@ -16560,9 +16560,9 @@
       }
     },
     "rollup": {
-      "version": "1.6.0",
-      "resolved": "https://registry.npmjs.org/rollup/-/rollup-1.6.0.tgz",
-      "integrity": "sha512-qu9iWyuiOxAuBM8cAwLuqPclYdarIpayrkfQB7aTGTiyYPbvx+qVF33sIznfq4bxZCiytQux/FvZieUBAXivCw==",
+      "version": "1.6.1",
+      "resolved": "https://registry.npmjs.org/rollup/-/rollup-1.6.1.tgz",
+      "integrity": "sha512-2giWBZjBepr/25vkds/EzpC52xySDyhX1wPGaJ69cnZJHCuYTzIJKFzJB1DTZ8C7A1FocBbG0KhS/No3whXmzw==",
       "dev": true,
       "requires": {
         "@types/estree": "0.0.39",
@@ -16571,9 +16571,9 @@
       },
       "dependencies": {
         "@types/node": {
-          "version": "11.11.3",
-          "resolved": "https://registry.npmjs.org/@types/node/-/node-11.11.3.tgz",
-          "integrity": "sha512-wp6IOGu1lxsfnrD+5mX6qwSwWuqsdkKKxTN4aQc4wByHAKZJf9/D4KXPQ1POUjEbnCP5LMggB0OEFNY9OTsMqg==",
+          "version": "11.11.4",
+          "resolved": "https://registry.npmjs.org/@types/node/-/node-11.11.4.tgz",
+          "integrity": "sha512-02tIL+QIi/RW4E5xILdoAMjeJ9kYq5t5S2vciUdFPXv/ikFTb0zK8q9vXkg4+WAJuYXGiVT1H28AkD2C+IkXVw==",
           "dev": true
         },
         "acorn": {

web3.js/package.json

@@ -111,7 +111,7 @@
     "marked": "^0.6.0",
     "prettier": "^1.14.3",
     "rimraf": "2.6.3",
-    "rollup": "1.6.0",
+    "rollup": "1.6.1",
     "rollup-plugin-babel": "^4.3.2",
     "rollup-plugin-commonjs": "9.2.1",
     "rollup-plugin-json": "^3.0.0",