* Fix invalid local uploads path
File upload provider does not consider the strapi configuration. This patch should fix the problem.
* getStaticPath -> uploadDir
* Use config.get method
* plugin-upload tests fix
the public folder shouldn't be hard-coded, it needs to follow the "strapi.config.public.path" value.
I faced this issue on my current project where i have a custom path for the "public" folder for development, replacing:
```
path.join(strapi.config.appPath, 'public', `uploads/${file.hash}${file.ext}`)
```
with
```
path.join(strapi.config.public.path, `/uploads/${file.hash}${file.ext}`)
```
solved my problem, so i need to notify you on this issue.
