Add antialias config option

Closes #41

spec/graphics/graphics_images_spec.rb

@@ -15,10 +15,13 @@ describe Squib::Card do
       allow(@deck).to receive(:dir).and_return('_output')
       allow(@deck).to receive(:count_format).and_return('%02d')
       allow(@deck).to receive(:prefix).and_return('card_')
+      allow(@deck).to receive(:antialias).and_return('best')
+
   end
 
   context '#png' do
     it 'makes all the expected calls on a smoke test' do
+      expect(@context).to receive(:antialias=).with('best')
       expect(@context).to receive(:save).once
       expect(@context).to receive(:translate).with(-37, -38).once
       expect(@context).to receive(:rotate).with(0.0).once
@@ -45,6 +48,7 @@ describe Squib::Card do
     it 'makes all the expected calls on a smoke test' do
       expect(@svg).to receive(:width).and_return(100).twice
       expect(@svg).to receive(:height).and_return(100).twice
+      expect(@context).to receive(:antialias=).with('best').once
       expect(@context).to receive(:save).once
       expect(@context).to receive(:rotate).with(0.0).once
       expect(@context).to receive(:translate).with(37, 38).once

spec/graphics/graphics_save_doc_spec.rb

@@ -20,13 +20,14 @@ describe Squib::Deck, '#save_pdf' do
     before(:each) do
       allow(Cairo::PDFSurface).to receive(:new).and_return(nil) #don't create the file
       allow(Cairo::Context).to    receive(:new).and_return(cxt)
+      allow(cxt).to receive(:antialias=)
     end
 
     it 'make all the expected calls on a smoke test' do
       num_cards = 9
       deck = Squib::Deck.new(cards: 9, width: 825, height: 1125)
-      expect(Squib.logger).to receive(:debug).at_least(:once)
       expect(deck).to receive(:dirify) { |arg| arg } #don't create the dir
+      expect(Squib.logger).to receive(:debug).at_least(:once)
 
       expect_card_place(75, 75)
       expect_card_place(831, 75)

spec/graphics/graphics_shapes_spec.rb

@@ -18,10 +18,12 @@ describe Squib::Card do
     allow(@deck).to receive(:dir).and_return('_output')
     allow(@deck).to receive(:count_format).and_return('%02d')
     allow(@deck).to receive(:prefix).and_return('card_')
+    allow(@deck).to receive(:antialias).and_return('best')
   end
 
   context 'rect' do
     it 'make all the expected calls on a smoke test' do
+      expect(@context).to receive(:antialias=).with('best')
       expect(@context).to receive(:save).once
       expect(@context).to receive(:rounded_rectangle).with(37, 38, 50, 100, 10, 15).twice
       expect_stroke('#fff', '#f00', 2.0)
@@ -36,6 +38,7 @@ describe Squib::Card do
 
   context 'circle' do
     it 'make all the expected calls on a smoke test' do
+      expect(@context).to receive(:antialias=).with('best')
       expect(@context).to receive(:save).once
       expect(@context).to receive(:move_to).with(137, 38)
       expect(@context).to receive(:circle).with(37, 38, 100).twice
@@ -51,6 +54,7 @@ describe Squib::Card do
 
   context 'triangle' do
     it 'make all the expected calls on a smoke test' do
+      expect(@context).to receive(:antialias=).with('best')
       expect(@context).to receive(:save).once
       expect(@context).to receive(:triangle).with(1, 2, 3, 4, 5, 6).twice
       expect_stroke('#fff', '#f00', 2.0)
@@ -63,6 +67,7 @@ describe Squib::Card do
 
   context 'line' do
     it 'make all the expected calls on a smoke test' do
+      expect(@context).to receive(:antialias=).with('best')
       expect(@context).to receive(:save).once
       expect(@context).to receive(:move_to).with(1, 2).once
       expect(@context).to receive(:line_to).with(3, 4).once

spec/graphics/graphics_text_spec.rb

@@ -14,11 +14,13 @@ describe Squib::Card, '#text' do
       allow(deck).to receive(:dir).and_return('_output')
       allow(deck).to receive(:count_format).and_return('%02d')
       allow(deck).to receive(:prefix).and_return('card_')
+      allow(deck).to receive(:antialias).and_return('best')
     end
 
     it 'make all the expected calls on a smoke test' do
       extent = Pango::Rectangle.new(50,60,100,200)
       expect(Squib.logger).to receive(:debug).once
+      expect(context).to receive(:antialias=).with('best').once
       expect(context).to receive(:save).once
       expect(context).to receive(:set_source_color).once
       expect(context).to receive(:move_to).with(10, 15).once
@@ -67,6 +69,7 @@ describe Squib::Card, '#text' do
       allow(deck).to receive(:dir).and_return('_output')
       allow(deck).to receive(:count_format).and_return('%02d')
       allow(deck).to receive(:prefix).and_return('card_')
+      allow(deck).to receive(:antialias).and_return('best')
     end
 
     it 'aligns right with strings' do