Pin down chef-gem's ohai dependency to 7.0.4

config/software/chef-gem.rb

 #
 # Copyright:: Copyright (c) 2012-2014 Chef Software, Inc.
+# Copyright:: Copyright (c) 2014 GitLab B.V.
 # License:: Apache License, Version 2.0
 #
 # Licensed under the Apache License, Version 2.0 (the "License");
@@ -20,6 +21,7 @@ default_version "11.12.2"
 dependency "ruby"
 dependency "rubygems"
+dependency "ohai"
 build do
   gem "install chef -n #{install_dir}/embedded/bin --no-rdoc --no-ri -v #{version}"

config/software/ohai.rb

+#
+# Copyright:: Copyright (c) 2014 GitLab B.V.
+# License:: Apache License, Version 2.0
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+#
+
+name "ohai"
+default_version "7.0.4"
+
+dependency "ruby"
+dependency "rubygems"
+
+build do
+  gem "install ohai -n #{install_dir}/embedded/bin --no-rdoc --no-ri -v #{version}"
+end