Dessert.t Fixes for warning

Hi,
Dessert.t throws a warning for me due to $. instead of .$ (see below).
```
rob@set $ prove -Ilib t/Dessert.t 
t/Dessert.t .. Use of uninitialized value $. in regexp compilation at t/Dessert.t line 11.
t/Dessert.t .. ok    
All tests successful.
Files=1, Tests=14,  1 wallclock secs ( 0.10 usr  0.00 sys +  0.62 cusr  0.06 csys =  0.78 CPU)
Result: PASS
```
This should fix it I believe.