Refactor Directories

Move Engine Files to /src Directory

lib/src/Cell.dart

@@ -0,0 +1,27 @@
+import 'package:rules_of_living/src/Rule.dart';
+
+class Cell {
+  bool state;
+  bool nextState = false;
+  List<Rule> surviveRules = new List<Rule>();
+  List<Rule> birthRules = new List<Rule>();
+
+  Cell([bool state = false]) : this.state = state;
+
+  void advanceState() {
+    this.state = this.nextState;
+    this.nextState = false;
+  }
+
+  void update(int neighbors) {
+    if (state == true) {
+      surviveRules.forEach( (Rule rule) {
+        if(rule.evaluate(neighbors) == true) this.nextState = true;
+      });
+    } else {
+      birthRules.forEach((Rule rule) {
+        if (rule.evaluate(neighbors) == true) this.nextState = true;
+      });
+    }
+  }
+}