Embed size fix

Missed the trailing word character in last commit

lib/squib/graphics/text.rb

@@ -109,7 +109,7 @@ module Squib
         rule          = embed.rules[key]
         spacing       = rule[:width] * Pango::SCALE
         index         = clean_str.index(key)
-        str.sub!(key, "<span size=\"0\">a<span letter_spacing=\"#{spacing.to_i}\">a</span></span>")
+        str.sub!(key, "<span size=\"0\">a<span letter_spacing=\"#{spacing.to_i}\">a</span>a</span>")
         layout.markup = str
         clean_str     = layout.text
         rect          = layout.index_to_pos(index)