go/analysis: remove "experimental" warning

The interface is now stable.

Change-Id: I7dc3feb70131cddb003f9320272a0fbd9b314048
Reviewed-on: https://go-review.googlesource.com/c/152597
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
diff --git a/go/analysis/doc.go b/go/analysis/doc.go
index 5dee615..f925849 100644
--- a/go/analysis/doc.go
+++ b/go/analysis/doc.go
@@ -3,10 +3,6 @@
 The analysis package defines the interface between a modular static
 analysis and an analysis driver program.
 
-
-THIS INTERFACE IS EXPERIMENTAL AND SUBJECT TO CHANGE.
-We aim to finalize it by November 2018.
-
 Background
 
 A static analysis is a function that inspects a package of Go code and