Integrate Poloniex

[einsteinx2]

• Poloniex client side authentication flow Poloniex client side authentication flow #10
  -Poloniex server side authentication flow Poloniex server side authentication flow #11 (not needed)
• Create PoloniexApi struct with static API functions Create PoloniexApi struct with static API functions #12
• Create PoloniexAccount object which parses the response Create PoloniexAccount object which parses the response #13
• Create function to create native Accounts from PoloniexAccounts Create function to create native Accounts from PoloniexAccounts #14

[einsteinx2]

Done