Sprint goals

• Prepare 0.5.0 for production #841
  • Improve status recognition #838
  • Filter out Twitter responses #837
• Implement multisignature pooling service #44
  • Multisignature support for other transaction types #173
  • Implement multisignature transaction validation schemes #170
  • Create deterministic ID generator #762
  • Add signature to multisignature transaction #161
  • Create API endpoint for multisignature transaction initiation (POST) #162
  • Create API endpoint for multisignature transaction update (PATCH) #163
  • Create API endpoint for transaction rejection (DELETE) #168
  • Request multisignature transaction rejection #167
  • Implement multisignature pool cleanup #176
  • Delegate status must be renamed to ineligible #843
  • Add multisignature account registration (POST) #172
  • Implement multisignature transaction validators #169