Add test for the line-height parameter

Author: fredj

test/index.test.js

@@ -9,6 +9,12 @@ describe('mapbox-to-css-font', function() {
       should(parseFont('Noto Sans Bold', 16)).eql('normal 700 16px "Noto Sans"');
       should(parseFont('Noto Sans SemiBold Italic', 16)).eql('italic 600 16px "Noto Sans"');
     });
+
+    it('handle line-height', function() {
+      should(parseFont('monospace', 16)).eql('normal 400 16px monospace');
+      should(parseFont('monospace', 16, 3.5)).eql('normal 400 16px/3.5 monospace');
+      should(parseFont('monospace', 16, '3em')).eql('normal 400 16px/3em monospace');
+    });
   });
 
 });