Fix typo and correct parameter types in the comments

src/tracer.js

@@ -46,14 +46,14 @@ export default class Tracer {
     _metrics: any;
 
     /**
-     * @param {string} [serviceName] - name of the current service or application.
-     * @param {object} [reporter] - reporter used to submit finished spans to Jaeger backend.
-     * @param {object} [sampler] - sampler used to decide if trace should be samlped when starting a new one.
-     * @param {object} [options] - the fields to set on the newly created span.
-     * @param {object} [options.tags] - set of key-value pairs which will be set
+     * @param {String} [serviceName] - name of the current service or application.
+     * @param {Object} [reporter] - reporter used to submit finished spans to Jaeger backend.
+     * @param {Object} [sampler] - sampler used to decide if trace should be sampled when starting a new one.
+     * @param {Object} [options] - the fields to set on the newly created span.
+     * @param {Object} [options.tags] - set of key-value pairs which will be set
      *        as process-level tags on the Tracer itself.
-     * @param {object} [options.metrics] - instance of the Metrics class from ./metrics/metrics.js.
-     * @param {object} [options.logger] - a logger matching NullLogger API from ./logger.js.
+     * @param {Object} [options.metrics] - instance of the Metrics class from ./metrics/metrics.js.
+     * @param {Object} [options.logger] - a logger matching NullLogger API from ./logger.js.
      */
     constructor(serviceName: string,
             reporter: Reporter = new NoopReporter(),