helpers.rb in kitchen-vagrant-1.7.1

- old
+ new

@@ -13,12 +13,12 @@
 # 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.
 
-require "mixlib/shellout"
-require "fileutils"
-require "json"
+require "mixlib/shellout" unless defined?(Mixlib::ShellOut)
+require "fileutils" unless defined?(FileUtils)
+require "json" unless defined?(JSON)
 
 module Kitchen
   module Driver
     module HypervHelpers
       def encode_command(script)