Bump version to 0.4

Change-Id: Iff812b9cb41b9ed6361f65b0451cbc11fb71413e

version.bzl

diff --git a/version.bzl b/version.bzl
index 7ac9881..c5200a7 100644
--- a/version.bzl
+++ b/version.bzl
@@ -4,4 +4,4 @@
 # we currently have no stable releases, we use the "build number" scheme
 # described at:
 # https://www.mojohaus.org/versions-maven-plugin/version-rules.html
-GITILES_VERSION = "0.3-7"
+GITILES_VERSION = "0.4"