Add a common component for stepped progress bar

[MAILPOET-1439]

assets/js/src/common/stepped_progess_bar.jsx

@@ -0,0 +1,27 @@
+import React from 'react';
+
+const SteppedProgressBar = (props) => {
+  if (props.step > props.steps_count) {
+    return null;
+  }
+  return (
+    <div className="mailpoet_stepped_progress_bar">
+      {
+        [...Array(props.steps_count).keys()].map(step => (
+          <div
+            className={`mailpoet_stepped_progress_bar_step ${(step < props.step ? 'active' : '')}`}
+            key={`step_${step}`}
+            style={{ width: `${Math.floor(100 / props.steps_count)}%` }}
+          />
+        ))
+      }
+    </div>
+  );
+};
+
+SteppedProgressBar.propTypes = {
+  steps_count: React.PropTypes.number.isRequired,
+  step: React.PropTypes.number.isRequired,
+};
+
+module.exports = SteppedProgressBar;