title: Rancher custom template version not seen during stack upgrade
body: <p>I am trying to manage a custom template with several versions, but rancher detects them in wrong order (or not detects them at all):</p>
  
  <p>I have 4 stack versions (in rancher-compose.yml) ordered by the following directories:</p>
  
  <p>0) "version: custom_branch"</p>
  
  <p>1) "version: stable"</p>
  
  <p>2) "version: 0.3"</p>
  
  <p>3) "version: 0.4"</p>
  
  <p>When installing a new stack all versions are seen - which is good!</p>
  
  <ul>
  <li>When trying to upgrade from "custom_branch" - "custom_branch" and "stable" are seen in template versions drop down</li>
  <li>When trying to upgrade from "stable" - only "stable" is seen</li>
  </ul>
  
  <p>(versions 0.3 and 0.4 are not seen during upgrade at all).</p>
  
  <p>I got a feeling that Rancher is taking the following version order instead of the expected:</p>
  
  <ul>
  <li>"0.3"</li>
  <li>"0.4"</li>
  <li>"custom_branch"</li>
  <li>"stable"</li>
  </ul>
  
  <p>Which means you cannot upgrade from custom_branch to 0.3. Are it suppose to take versions order of directory numbers?</p>
  
  <p>Example of my rancher-compose.yml:
  <code>
  .catalog:
    name: "NAME"
    version: "0.3"
    description: "My Stack"
    minimum_rancher_version: v1.6.10
    maximum_rancher_version: v1.6.14
    questions:
      - variable: "HOST_DOMAIN"
        description: "Domain address of the Rancher host"
        label: "Host Domain"
        required: true
        default: "example.net"
        type: "string"
  </code></p>
  
  <p><strong>Rancher versions:</strong>
  rancher/server: 1.6.14
  rancher/agent: 1.2.9</p>