Fixes #53: --css required to write a CSS file.

Author: zachleat

cmd.js

@@ -61,7 +61,7 @@ if( argv.subset ) {
 // glyphhanger --subset=*.ttf --US_ASCII										(reduce to US_ASCII characters)
 // glyphhanger --subset=*.ttf --US_ASCII --whitelist=ABCD		(reduce to US_ASCII union with whitelist)
 // glyphhanger --family='My Serif'													(outputs results for specific family)
-// glyphhanger --family='My Serif' -css											(outputs results for specific family with a font-face block)
+// glyphhanger --family='My Serif' --css										(outputs results for specific family with a font-face block)
 // glyphhanger --subset=*.ttf --family='My Serif'						(subset group of fonts to results for specific family)
 // glyphhanger --subset=*.ttf --family='My Serif' -css			(subset group of fonts to results for specific family and a font-face block)
 // glyphhanger --subset=*.ttf --output=dist/								(change the output directory for subset files)

src/GlyphHangerFontFace.js

@@ -70,7 +70,7 @@ ${content.join("\n")}
 	}
 
 	writeCSSFiles() {
-		if(!this.subset) {
+		if(!this.subset || !this.cssOutput) {
 			return;
 		}