Added note about Analytics-Swift Pilot to Readme.

Author: bsneed

README.md

@@ -1,3 +1,9 @@
+## Developer Feedback Requested: Analytics-Swift Pilot
+
+**A pilot release of the new Analytics-Swift library is available at the [Analytics-Swift repository](https://github.com/segmentio/analytics-swift). This library is governed by [Segment’s First-Access and Beta terms](https://segment.com/legal/first-access-beta-preview/), and should not be used in production scenarios.**
+
+During the pilot phase, Segment wants your feedback, contributions, and ideas. If you have requirements or ideas for features for Analytics-Swift and Segment's integration with the Apple platform, let us know.
+
 # Analytics
 [![Circle CI](https://circleci.com/gh/segmentio/analytics-ios.svg?style=shield&circle-token=31c5b3e5edeb404b30141ead9dcef3eb37d16d4d)](https://circleci.com/gh/segmentio/analytics-ios)
 [![Version](https://img.shields.io/cocoapods/v/Analytics.svg?style=flat)](https://cocoapods.org//pods/Analytics)