Fixing bug in image override in deploy subcommand

• Fixed the image override function, that was not being triggered since its condition was reversed.

Removed unneeded exception import

• Fixed a bug were an import of a removed exception was still in the code

Removed Cluster default creation

Breaking change

• Ecs cluster were provisioned and decommissioned automatically by the CLI if the "computeStack" field is set to "True" in any of the stacks. Now, the cluster should be included inside the cloudformation template that will have the "computeStack" set to "True"

Support for external stacks

• Climulon now supports use of external stacks outputs in along with what is in the Master Config Files
• External stacks can be defined in the MCF this way :

{
   "externalStacks": [
      {
         "StackName": "Example_name",
         "StackRegion": "us-east-1"
      }
   ],
   ...
}

Deploy Image overwrite

BREAKING CHANGE

• Climulon was using the codeship CI variables in order to know what new images to deploy. We now have the option --image in order to define each image the variables defined in the master config file should have.
• This change will break the former implementation.

Travis-ci integration

• Now building docker image for climulon in Travis-ci
• Now pushing to docker hub all the releases with their tags + latest
• Added build status icon

Python3 and symlink

• Made the CLI run by default on python3
• Installed python3 in the docker image
• Created a symlink to the cli in the docker image. To run the cli from the docker image, you now have to use this :

docker run shrobs/climulon climulon

First OSS release

0.1.0

fixing typo in readme