internal/lsp: update version string in preparation for gopls/0.3.1-pre1

Change-Id: Ie6429d0db66c22742d1d0f87a5b7bfc887b51d54
Reviewed-on: https://go-review.googlesource.com/c/tools/+/217717
Reviewed-by: Robert Findley <rfindley@google.com>
diff --git a/internal/lsp/debug/info.go b/internal/lsp/debug/info.go
index 6cd8ad5..dff564a 100644
--- a/internal/lsp/debug/info.go
+++ b/internal/lsp/debug/info.go
@@ -21,7 +21,7 @@
 )
 
 // Version is a manually-updated mechanism for tracking versions.
-var Version = "v0.3.0"
+var Version = "v0.3.1"
 
 // PrintServerInfo writes HTML debug info to w for the Instance s.
 func PrintServerInfo(w io.Writer, s Instance) {