text weight: respect lfseries

Author: nschloe

matplotlib2tikz/text.py

@@ -160,6 +160,8 @@ def draw_text(data, obj):
             'black'
             ] or (isinstance(weight, int) and weight > 550):
         style.append('\\bfseries')
+    elif weights == 'light' or (isinstance(weight, int) and weight < 300):
+        style.append('\\lfseries')
 
     if obj.axes:
         # If the coordinates are relative to an axis, use `axis cs`.