remove shadow from gradient button

lib/ui/common/gradientButton.dart

@@ -16,14 +16,6 @@ class GradientButton extends StatelessWidget {
       child: Container(
         height: 56,
         decoration: BoxDecoration(
-          boxShadow: [
-            BoxShadow(
-              spreadRadius: 0,
-              offset: Offset(0, 4),
-              color: Colors.black.withOpacity(0.2),
-              blurRadius: 2,
-            )
-          ],
           gradient: LinearGradient(
             begin: Alignment(0.1, -0.9),
             end: Alignment(-0.6, 0.9),