Add test link in readme (#26)

* Add test link in readme
* Add Che badge at the top as well
* Add license badge

Signed-off-by: David Festal <dfestal@redhat.com>

README.md

@@ -1,5 +1,12 @@
 # Kube-native API for cloud development workspaces specification
 
+<div id="header" align="center">
+
+[![Eclipse License](https://img.shields.io/badge/license-Eclipse-brightgreen.svg)](LICENSE)
+[![Contribute](https://che.openshift.io/factory/resources/factory-contribute.svg)](https://che.openshift.io/f/?url=https://github.com/che-incubator/devworkspace-api)
+
+</div>
+
 Sources for this API are defined in Go code, starting from the
 [devworkspace_types.go source file](pkg/apis/workspaces/v1alpha1/devworkspace_types.go)
 
@@ -28,4 +35,16 @@ In the root directory, just run the following command:
 ``` 
 ## Specification status
 
-This work is still in an early stage of specification, and the related API and schemas are still a draft proposal. 
+This work is still in an early stage of specification, and the related API and schemas are still a draft proposal.
+
+## Quickly open and test ?
+
+In order to test existing or new Devfile 2.0 or DevWorkspace sample files in a self-service Che workspace (hosted on che.openshift.io), just click on the button below:
+
+[![Contribute](https://che.openshift.io/factory/resources/factory-contribute.svg)](https://che.openshift.io/f/?url=https://github.com/che-incubator/devworkspace-api)
+
+As soon as the workspace is opened, you should be able to:
+- open the `yaml` files in the following folders:
+  - `samples/`
+  - `devfile-support/samples`
+- have `yaml` language support (completion and documentation) based on the current Json schemas.