Collect W8/W9

[super3]

Per tax law we need to collect a W8/W9 from a user before they exceed $600 in payouts. Below this limit the user filling out the from is completely voluntary. If they don't fill it out before the $600 in payouts we have to stop payouts and cut contracts until they have completed it.

Forms:

• W9 - To be completed if they are in the US
• W8 - To be completed if they are international

@boshevski Need you to prototype our those forms in the interface.

Todo:

• @boshevski Prototype design W8 form
• @boshevski Prototype design W9 form
• Discuss method to encrypt/send info to Storj Labs

[super3]

Once this is complete it will be implemented in storj-archived/storjshare-gui#114