add comment and also refactoring for dbConn.Close()

Fix for goroutine leak (#7)

* Fix context leak
* make unlocker channel buffered

Co-authored-by: Ankur Singh <ankur@cashfree.com>

Add MySQL timeout parameter / fix compatibility with MariaDB 10.1 and…

… older (#3)

* Fix compatibility with MariaDB 10.1 and older

* Add missing cancel function call for context in ObtainTimeoutContext, fix comments

* Add MariaDB 10.1 as test target in Azure pipeline, remove oldmysql tag for tests with older MySQL versions

* Update README.md: add documentation for new functions and a "compatibility" section

release lock on connection error; improved test

change golang version to 1.13; enable pipelines in dev branch

fix README example