fix: packages/opencensus-instrumentation-http/package.json & packages/opencensus-instrumentation-http/package-lock.json to reduce vulnerabilities (#746)

The following vulnerabilities are fixed with an upgrade:
- https://snyk.io/vuln/SNYK-JS-CODECOV-543183

Author: snyk-bot

packages/opencensus-instrumentation-http/package-lock.json

@@ -54,7 +54,7 @@
     "@types/node": "^9.4.7",
     "@types/semver": "^6.0.0",
     "@types/shimmer": "^1.0.1",
-    "codecov": "^3.5.0",
+    "codecov": "^3.6.2",
     "gts": "^1.0.0",
     "mocha": "^6.1.0",
     "nock": "^10.0.0",