fix(getting-started): remove extra comma (open-telemetry#704)

add ts-node package

closes open-telemetry#703

Signed-off-by: Olivier Albertini <olivier.albertini@montreal.ca>

Author: OlivierAlbertini

getting-started/ts-example/package.json

@@ -5,10 +5,13 @@
   "main": "app.ts",
   "scripts": {
     "start": "ts-node app.ts",
-    "start-tracing": "ts-node -r ./tracing.ts app.ts",
+    "start-tracing": "ts-node -r ./tracing.ts app.ts"
   },
   "author": "OpenTelemetry Authors",
   "license": "Apache-2.0",
+  "devDependencies": {
+    "ts-node": "^8.6.2"
+  },
   "dependencies": {
     "@opentelemetry/core": "^0.3.2",
     "@opentelemetry/exporter-prometheus": "^0.3.2",
@@ -18,7 +21,7 @@
     "@opentelemetry/plugin-http": "^0.3.2",
     "@opentelemetry/tracing": "^0.3.2",
     "@opentelemetry/types": "^0.3.2",
-    "axios": "^0.19.0",
+    "axios": "^0.19.1",
     "express": "^4.17.1"
   }
 }