* feat: make client to wait when no free connections
* feat: make client to wait when no free connections
use AcquireTimer to do timeout instead of using context
* feat: make client to wait when no free connections
Add BenchmarkClientGetEndToEndWaitConn* to test heap allocation
in waiting for free connection situation
* feat: make client to wait when no free connections
Add BenchmarkHTTPClientGetEndToEndWaitConn* to test heap allocation
in waiting for free connection situation
* feat: make client to wait when no free connections
fix bug in BenchmarkHTTPClientGetEndToEndWaitConn*
* feat: make client to wait when no free connections
fix bug in TestHostClientMaxConnWaitTimeoutSuccess make it wait
longer to avoid ErrNoFreeConns on travis-ci
* feat: make client to wait when no free connections
fix do not compile benchmark(NetHTTP?)ClientGetEndToEndWaitConn
if go version < 1.11.x
* feat: make client to wait when no free connections
fix the bug that if deadline is earlier than MaxConnWaitTimeout,
still wait MaxConnWaitTimeout which later than deadline.
* feat: make client to wait when no free connections
fix race condition in TestHostClientMaxConnWaitTimeoutError
* feat: make client to wait when no free connections
fix bug in TestHostClientMaxConnWaitTimeoutWithEarlierDeadline