chore: bump rxjs from 6.5.5 to 6.6.0

Bumps [rxjs](https://github.com/reactivex/rxjs) from 6.5.5 to 6.6.0.
- [Release notes](https://github.com/reactivex/rxjs/releases)
- [Changelog](https://github.com/ReactiveX/rxjs/blob/6.6.0/CHANGELOG.md)
- [Commits](ReactiveX/rxjs@6.5.5...6.6.0)

Signed-off-by: dependabot[bot] <[email protected]>

Author: dependabot[bot]

package-lock.json

@@ -106,7 +106,7 @@
     "rollup-plugin-commonjs": "^10.1.0",
     "rollup-plugin-sourcemaps": "^0.6.2",
     "rollup-plugin-typescript2": "^0.27.1",
-    "rxjs": "6.5.5",
+    "rxjs": "6.6.0",
     "semantic-release": "17.0.8",
     "ts-jest": "^26.1.0",
     "tslint": "^6.1.2",