First app init & push implementation

[ziccardi]

Motivation

Jiras:

• https://issues.jboss.org/browse/AEROGEAR-9864
• https://issues.jboss.org/browse/AEROGEAR-10043
• https://issues.jboss.org/browse/AEROGEAR-10047
• https://issues.jboss.org/browse/AEROGEAR-10046

Changelog

1. Added a WorkspaceManager class to be used to manage the workspace and the objects contained into the workspace
2. Added a KubeClient wrapper class to simplify the interaction with the kube apis.
3. Added app init command implementation
4. Added push command implementation
5. Put in place a basic structure to be able to support multiple applications
6. Added a spinner for long operations

Verification

1. login to openshift with kubectl or oc
2. clone this BRANCH
3. run make install
4. run the command as kubectl ag: that will show some help about the available ag commands
5. create an app running kubectl ag app init my-wonderful-app
6. check that an .ag folder is created in the current directory and that it contains the json of your new application
7. push the application with kubectl ag push
8. check that application is visible into MDC if you have it running, otherwise check that the CR has been created in the correct namespace.
9. when finished with the tests, run make uninstall

Examples

Creating an application

$ kubectl ag app init myapp

Pushing an app to the server

$ kubectl ag push

[ziccardi]

@wtrocki All your concerns should be now addressed