update swift to beta (#1018)

Author: prayansh

README.md

@@ -1,8 +1,8 @@
-## Developer Feedback Requested: Analytics-Swift Pilot
+## Developer Feedback Requested: Analytics-Swift Beta
 
-**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.**
+**A beta 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.
+During the beta 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.
 
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