Implement ineffectual shader for basis testing.

assets/shader_programs/test_fragment.glsl

@@ -4,6 +4,8 @@
 precision mediump float;
 #endif
 
+attribute vec4 gl_Color;
+
 uniform vec2 u_resolution;
 uniform float u_time;
 
@@ -42,4 +44,7 @@ void main(){
     color = hsb2rgb(vec3(st.x,1.0,st.y));
 
     gl_FragColor = vec4(color,1.0);
+
+
+    gl_FragColor = gl_Color;
 }