chore(deps): update dependency ts-mocha to v7 (#781)

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

Author: renovate[bot]

packages/opencensus-core/package-lock.json

@@ -64,7 +64,7 @@
     "intercept-stdout": "^0.1.2",
     "mocha": "^7.0.0",
     "nyc": "14.1.1",
-    "ts-mocha": "^6.0.0",
+    "ts-mocha": "^7.0.0",
     "ts-node": "^8.0.0",
     "typescript": "~2.9.0"
   },

packages/opencensus-core/package.json

@@ -58,7 +58,7 @@
     "mocha": "^7.0.0",
     "nock": "^10.0.0",
     "nyc": "14.1.1",
-    "ts-mocha": "^6.0.0",
+    "ts-mocha": "^7.0.0",
     "ts-node": "^8.0.0",
     "typescript": "~3.2.0"
   },

packages/opencensus-exporter-instana/package-lock.json

@@ -58,7 +58,7 @@
     "nock": "^10.0.0",
     "nyc": "^14.0.0",
     "rimraf": "^3.0.0",
-    "ts-mocha": "^6.0.0",
+    "ts-mocha": "^7.0.0",
     "ts-node": "^8.0.0",
     "typescript": "~3.2.0"
   },