README.md in kitchen-docker-2.2.0 vs README.md in kitchen-docker-2.3.0

@@ -2,11 +2,11 @@
 
 A Test Kitchen Driver for Docker.
 
 ## Requirements
 
-* [Docker][docker_installation] **(>= 1.2)**
+* [Docker][docker_installation] **(>= 1.5)**
 
 ## Installation and Setup
 
 Please read the Test Kitchen [docs][test_kitchen_docs] for more details.
 
@@ -414,9 +414,23 @@
 
 ```
 devices:
   - /dev/vboxdrv
   - /dev/vboxnetctl
+```
+
+### build_context
+
+Transfer the cookbook directory (cwd) as build context. This is required for
+Dockerfile commands like ADD and COPY. When using a remote Docker server, the
+whole directory has to be copied, which can be slow.
+
+The default value is `true` for local Docker and `false` for remote Docker.
+
+Examples:
+
+```yaml
+  build_context: true
 ```
 
 ## Development
 
 * Source hosted at [GitHub][repo]