feat(button): add a debounce time option

lib/button.js

@@ -183,15 +183,6 @@ function Button(opts) {
     last: null
   };
 
-  // Create a debounce boundary on event triggers
-  // this avoids button events firing on
-  // press noise and false positives
-  var trigger = Fn.debounce(function(key) {
-    aliases[key].forEach(function(type) {
-      this.emit(type);
-    }, this);
-  }, 7);
-
   pinValue = typeof opts === "object" ? opts.pin : opts;
 
   Board.Component.call(
@@ -223,6 +214,11 @@ function Button(opts) {
 
   this.pulldown = opts.pulldown || opts.isPulldown || false;
 
+  // `debounceTime` is a duration (milliseconds)
+  // to prevent button events firing on
+  // press noise and false positives
+  this.debounceTime = opts.debounceTime || 7;
+
   // Turns out some button circuits will send
   // 0 for up and 1 for down, and some the inverse,
   // so we can invert our function with this option.
@@ -291,6 +287,15 @@ function Button(opts) {
     }
   });
 
+  // Create a debounce boundary on event triggers
+  // this avoids button events firing on
+  // press noise and false positives
+  var trigger = Fn.debounce(function(key) {
+    aliases[key].forEach(function(type) {
+      this.emit(type);
+    }, this);
+  }, this.debounceTime);
+
   /* istanbul ignore else */
   if (typeof this.initialize === "function") {
     this.initialize(opts, function(data) {