Added Groups to Artist, Added StatusErrTooManyRequests error handler

#53
#50

Raise go and vendor versions

v0.3.3

Raise go version (#48)

v0.3.1

• Added endpoints
  • User Collection
    • Collection Folders
    • Folder
    • Collection Items by Folder
    • Collection Items by Release
  • Marketplace
    • Price Suggestions
    • Release Statistics

• Refreshed vendors

Functions moved to interface

#40

no backward compatibility,
check your code and use discogs.Search() instead of discogs.Search.Search() and discogs.* instead of discogs.Database().*

Minor improvements in database

• Added missed fields to Release (#37)
• go mod updated (go version updated, vendor libs updated) (#38)

Fixed some data in database

#36

Minor improvement

Added MasterID to Search.Result #34

Minor fix

Fixed Search #32

Removed vendor, some minor code optimizations

v0.2

Travis version updated

Use go mod

Supported go mod