Add buildbot user info for tag step

buildbot/buildbot_steps.sh

@@ -165,12 +165,17 @@ function tag_head_and_push() {
 
     cd "$git_repo_dir"
 
+    git config user.name "BuildBot"
+    git config user.email "buildbot@bitmessage.io"
+
     git tag -n | grep $(git rev-parse HEAD)
     if [ $? -eq 0 ]; then
         >&2 echo 'HEAD tag already exists, bailing out...'
         return 1
     fi
 
+ 
+
     git tag -a "g_$(git rev-parse HEAD)" HEAD -m "BuildBot: tag commit for release $(git rev-parse HEAD)" || return 2
     git push --tags "$remote" "$branch"
     if [ $? -ne 0 ]; then