[Marketplace] Cannot upload images as a guest seller

[JoeyLyman]

Expected behavior

When creating a product as a guest seller, I expect to be able to click on the default image (with the +) and upload an image.

Actual Behavior

Can select a file, but the image does not update on the product (the image stays as the placeholder, both on the product page and on the product grid).

Steps to Reproduce the Behavior

Create a guest seller account (not admin), add a new product, and try to upload an image

Versions

Node: 8.2.1
NPM: 5.3.0
Meteor Node: 4.8.4
Meteor NPM: 4.6.1
Reaction CLI: 0.12.0
Reaction: 1.5.0
Reaction branch: marketplace

[kieha]

Was able to reproduce this issue. Tried adding an image to a product created as an invited shop owner, and got these console errors:

Most likely has something to do with permissions.

[impactmass]

PR #2918 Referenced above is the PR for this issue .. currently going through review.

[impactmass]

resolved in #2918