Add documentation. Add options to enable/disable the hash providers. Add the option for setup barrier for rotation per requests strategy.

src/main/java/io/kamax/mxisd/hash/rotation/RotationPerRequests.java

@@ -8,6 +8,11 @@ public class RotationPerRequests implements HashRotationStrategy {
 
     private HashEngine hashEngine;
     private final AtomicInteger counter = new AtomicInteger(0);
+    private final int barrier;
+
+    public RotationPerRequests(int barrier) {
+        this.barrier = barrier;
+    }
 
     @Override
     public void register(HashEngine hashEngine) {
@@ -23,7 +28,7 @@ public class RotationPerRequests implements HashRotationStrategy {
     @Override
     public synchronized void newRequest() {
         int newValue = counter.incrementAndGet();
-        if (newValue >= 10) {
+        if (newValue >= barrier) {
             counter.set(0);
             trigger();
         }