add Slider component boilerplate

components/slider.cpp

@@ -1 +1,10 @@
 #include "slider.h"
+
+Slider::Slider(QWidget *parent)
+    : QWidget(parent)
+{
+}
+
+Slider::~Slider()
+{
+}

components/slider.h

@@ -0,0 +1,15 @@
+#ifndef SLIDER_H
+#define SLIDER_H
+
+#include <QWidget>
+
+class Slider : public QWidget
+{
+    Q_OBJECT
+
+public:
+    explicit Slider(QWidget *parent = 0);
+    ~Slider();
+};
+
+#endif // SLIDER_H