3.0.0-a.4

• Drop deprecated quantity fields - #902 by @maarcingebala
• Fix warnings - #919 by @MarekChoinski
• Fix icons rendering issue in shipping rates table - #916 by @MarekChoinski
• Drop authorization keys section - #913 by @maarcingebala, @dominik-zeglen
• Ability to add shipping zone's description - @tomaszszymanski129