Add mutex

Mutex added to each function to prevent race condition. Some tests were refactored by removing Lock-Unlock
function calls.

Signed-off-by: gozeloglu <[email protected]>

Add Keys function

Keys() method added for listing stored keys in database. Usage added in README and pkg/main.go.

Signed-off-by: Gökhan Özeloğlu <[email protected]>

Add Exists function

Exists function added. Tests written for that function. pkg/main.go and README updated with Exists example

Signed-off-by: Gökhan Özeloğlu <[email protected]>

Add IncrBy function

IncrBy function added as a new feature. Example code added to pkg/main.go and README.

Signed-off-by: Gökhan Özeloğlu <[email protected]>

Update README

Duplicate badge removed

Fix db test interval time

Add server log lines

Update doc.go

* Updated README. Badge added for LICENSE.
* addr in Kvs struct type made exported variable.
* Doc comments added for struct types

Add doc.go

Add time interval for saving data periodically

* Time interval for saving data periodically feature implemented by using ticker and goroutine.
* Functions that was affected due to adding parameters to functions refactored.
* Lock-Unlock calling changed in functions.
* README and example codes updated.