Error Handling Update: Version Checking, ddev availability, ddev error codes

[andrew-c-tran]

Feature Request

With the introduction of JSON endpoints in the CLI, we need a version checking mechanism to error out when a < 0.9.4 version is detected as ddev list and ddev describe is critical for any sort of UI functionality. We've agreed that string parsing is fragile, and as such should not be supported.

What you expected to happen:

Discussion is needed on how to error out. This is a show stopper, text parsing of ddev-list and ddev-describe is to be completely removed. If an incompatible version is detected, how do we want to error out and show the customer? Do we simply show a warning and exit? Do we launch a browser window to ddev download site? etc.

Related source links or issues:

Initial version check discussion brought up in #18

[rfay]

This needs to handle many other cases as well:

• ddev not available
• ddev list fails (or any other command failure)

[andrew-c-tran]

as of v0.2, the minimum version of ddev cli required by ddev-ui is now 0.11

[andrew-c-tran]

to be addressed in #42 . closing issue.