Update beta to version with fixed FreeBSD support from #49023.

bdrewery · bdrewery · commit 57c74c39813c · 2018-03-19T12:40:42.000-07:00
Fixes #42681
diff --git a/src/stage0.txt b/src/stage0.txt
@@ -12,7 +12,7 @@
 # source tarball for a stable release you'll likely see `1.x.0` for rustc and
 # `0.x.0` for Cargo where they were released on `date`.
 
-date: 2018-02-20
+date: 2018-03-18
 rustc: beta
 cargo: beta
 
