Tweaked minFlingVelocity in swipe dismiss listener

To reflect the change made here
https://code.google.com/p/dashclock/source/browse/main/src/com/google/android/apps/dashclock/ui/SwipeDismissListViewTouchListener.java

certainly seems to make the swipe action a lot more usable.
Merge pull request #15 from storkme/master

Tweaked SwipeDismissListViewTouchListener