Ticker leaks if timeout is used

[fako1024]

When using a timeout for a request a time.Ticker is created for every retry attempt. Aside from the fact that a ticker isn't the optimal tool for this (a time.Timer would be better suited), Stop() is never called and hence the ticker will receive events for all eternity (which can accumulate quite a lot of resources if timeouts are used repeatedly):

      flat  flat%   sum%        cum   cum%
    1500ms 31.06% 31.06%     1500ms 31.06%  runtime.siftdownTimer /usr/local/go/src/runtime/time.go:1112
     630ms 13.04% 44.10%      630ms 13.04%  runtime.siftdownTimer /usr/local/go/src/runtime/time.go:1118
     590ms 12.22% 56.31%      590ms 12.22%  runtime/internal/syscall.Syscall6 /usr/local/go/src/runtime/internal/syscall/asm_linux_amd64.s:36
     380ms  7.87% 64.18%      380ms  7.87%  runtime.chansend /usr/local/go/src/runtime/chan.go:193
     190ms  3.93% 68.12%      190ms  3.93%  runtime.siftdownTimer /usr/local/go/src/runtime/time.go:1111
     180ms  3.73% 71.84%      180ms  3.73%  time.Now /usr/local/go/src/time/time.go:1111
     170ms  3.52% 75.36%      170ms  3.52%  runtime.siftdownTimer /usr/local/go/src/runtime/time.go:1130
      90ms  1.86% 77.23%       90ms  1.86%  runtime.siftdownTimer /usr/local/go/src/runtime/time.go:1122
      70ms  1.45% 78.67%       70ms  1.45%  runtime.lock2 /usr/local/go/src/runtime/lock_futex.go:61
      60ms  1.24% 79.92%       60ms  1.24%  runtime.siftdownTimer /usr/local/go/src/runtime/time.go:1124