Fix specification of gray level in slider_demo; thanks to Matthias Michler

svn path=/trunk/matplotlib/; revision=6425

Author: efiring

examples/widgets/slider_demo.py

@@ -26,7 +26,7 @@ def update(val):
 samp.on_changed(update)
 
 resetax = axes([0.8, 0.025, 0.1, 0.04])
-button = Button(resetax, 'Reset', color=axcolor, hovercolor=0.975)
+button = Button(resetax, 'Reset', color=axcolor, hovercolor='0.975')
 def reset(event):
     sfreq.reset()
     samp.reset()