Updated to build and test with Bazel 1.0 official release.

Change-Id: Ie47df8a3a11aeeb11b6c5f43cc1608827f8ddf8f
diff --git a/tools/build/bazel/bazel_version.bzl b/tools/build/bazel/bazel_version.bzl
index 9a0046e..5ee5489 100644
--- a/tools/build/bazel/bazel_version.bzl
+++ b/tools/build/bazel/bazel_version.bzl
@@ -22,6 +22,6 @@
         return
 
     versions = native.bazel_version.split(".")
-    if not int(versions[1]) >= 27:
-        fail("\nBazel version %s is not supported; please use 0.27.* official release!\n\n" %
+    if not int(versions[0]) >= 1:
+        fail("\nBazel version %s is not supported; please use 1.0.* official release!\n\n" %
              native.bazel_version)