HTTP timeout variable moved from bittrex.go to client struct in client.go file to achieve easier configurability.
Added new initialization functions to create new client with specified timeout value.
When passing custom HttpClient, its Timeout value is also set to httpTimeout field in client struct.
HttpTimeout value in client struct is used in connectTimer.
HTTP timeout variable moved from bittrex.go to client struct in client.go file to achieve easier configurability. Added new initialization functions to create new client with specified timeout value. When passing custom HttpClient, its Timeout value is also set to httpTimeout field in client struct. HttpTimeout value in client struct is used in connectTimer.