Bump @opentelemetry/core from 0.16.0 to 0.18.0 (#317)

Bumps [@opentelemetry/core](https://github.com/open-telemetry/opentelemetry-js) from 0.16.0 to 0.18.0.
- [Release notes](https://github.com/open-telemetry/opentelemetry-js/releases)
- [Changelog](https://github.com/open-telemetry/opentelemetry-js/blob/main/CHANGELOG.md)
- [Commits](open-telemetry/opentelemetry-js@v0.16.0...v0.18.0)

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

Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

package.json

@@ -58,7 +58,7 @@
     "supertest": "^6.0.1"
   },
   "dependencies": {
-    "@opentelemetry/core": "^0.16.0",
+    "@opentelemetry/core": "^0.18.0",
     "array-flatten": "^3.0.0",
     "debug": "^4.2.0",
     "libhoney": "^2.2.1",