samples: fix to be more consistent

samples/shapes/_proofs.rb

@@ -13,7 +13,7 @@ end
 Squib::Deck.new(width:'2in', height: '1in')do
   background color: :white
   safe_zone stroke_color: :purple, margin: '0.1in'
-  safe_zone stroke_color: :purple, margin: '0.05in'
+  cut_zone stroke_color: :purple, margin: '0.05in'
 
   text str: 'Small card with proof lines', x: '0.1in', y: '0.1in',
        font: 'Arial 10'

spec/data/samples/shapes/_proofs.rb.txt

@@ -76,10 +76,10 @@ cairo: rounded_rectangle([15.0, 15.0, 570.0, 270.0, 37.5, 37.5])
 cairo: set_source_color(["#0000"])
 cairo: fill_preserve([])
 cairo: set_source_color(["purple"])
-cairo: set_line_width([1.0])
+cairo: set_line_width([2.0])
 cairo: set_line_join([0])
 cairo: set_line_cap([0])
-cairo: set_dash([[3.0, 3.0]])
+cairo: set_dash([[]])
 cairo: stroke([])
 cairo: restore([])
 cairo: save([])