Update reportlab from 3.3.0 to 3.4.0

Author: pyup-bot

requirements/doc.txt

@@ -2,7 +2,7 @@
 docutils==0.13.1
 requests[security]==2.13.0
 sphinx==1.5.3
-reportlab==3.3.0
+reportlab==3.4.0
 alabaster==0.7.10
 releases==1.3.0 # Updated from 1.2.0
 aafigure==0.5