Error handling incomplete for duplicate named functions

[X] Bug
[ ] Feature
[ ] Enhancement

Detailed Description

When creating a function that has the same name as an existing function the following error is surfaced.

Action:

dispatch create --file seed.yaml
[Code: 400] Bad request: store error when adding base image

Validate existing functions:

dispatch get functions
    NAME   |  IMAGE  | STATUS |         CREATED DATE
----------------------------------------------------------
  http-py  | python3 | READY  | Sat Jan  1 10:13:24 AEST 0000
  hello-py | python3 | READY  | Sat Jan  1 10:13:24 AEST 0000
  hello-js | nodejs6 | READY  | Sat Jan  1 10:13:24 AEST 0000

Check batch:

cat seed.yaml | grep http-py
name: http-py

The error ([Code: 400] Bad request: store error when adding base image) does not have any bearing on the actual error of unique function names.

Workaround: change name of function or delete existing named function. Validate: dispatch get functions

Context

The error does not indicate what is wrong or why the function import failed. A user will understand what the cause is and fix this.

Possible Implementation

Handle unique names to throw an error correction.

Complexity

Low due to known problem space - unique function names

[x ] Low - Simple enhancement or bug fix, no architectural changes or refactoring
[ ] Medium - Change requires some thought, but is relatively isolated
[ ] High - Significant architectural change or large refactor

Impact

[x ] Low - Annoyance, but does not impact business or functionality
[] Medium - Issue can be worked around, but is causing pain
[ ] High - Blocker

Your Environment

Dispatch CLI version (or git commit): latest
Dispatch Chart version (or image[s] tag):
Operating System and version: macos 10.13.3
Kubernetes version (and distribution): minikube 1.8.1
Etc (any other useful environmental information):

vmware-archive / dispatch