Fix tools unittest on canaries.

BUG=chromium-os:39079
TEST=CHROMEOS_OFFICIAL=1 USER=chrome-bot ./tools.py --test

Change-Id: I65fbd288f7a02c966b0a42635e6220911d611694
Reviewed-on: https://gerrit.chromium.org/gerrit/43621
Commit-Queue: David James <davidjames@chromium.org>
Tested-by: David James <davidjames@chromium.org>
Reviewed-by: Mike Frysinger <vapier@chromium.org>
diff --git a/host/lib/tools.py b/host/lib/tools.py
index 815932a..3d4a0a3 100755
--- a/host/lib/tools.py
+++ b/host/lib/tools.py
@@ -555,7 +555,7 @@
     """
     tools = self.tools
 
-    re_version_pattern = '^\d{4}.\d+.\d{4}_\d{2}_\d{2}_\d+$'
+    re_version_pattern = '^\d{4}.\d+.(?:\d{4}_\d{2}_\d{2}_\d+|\d+)$'
     re_version = re.compile(re_version_pattern)
     reported_version = tools.GetChromeosVersion()
     self.assertTrue(re_version.match(reported_version),