* Added context for the MasterClient's methods to avoid endless loops
* Returned WithClient function. Added WithClientCustomGetMaster function
* Hid unused ctx arguments
* Using a common context for the KeepConnectedToMaster and WaitUntilConnected functions
* Changed the context termination check in the tryConnectToMaster function
* Added a child context to the tryConnectToMaster function
* Added a common context for KeepConnectedToMaster and WaitUntilConnected functions in benchmark
The io/ioutil package has been deprecated as of Go 1.16, see
https://golang.org/doc/go1.16#ioutil. This commit replaces the existing
io/ioutil functions with their new definitions in io and os packages.
Signed-off-by: Eng Zer Jun <engzerjun@gmail.com>