Don't build docs by default, which causes issues when trying
to remove .txt files, as they will be readded on installing.

--- a/setup.py
+++ b/setup.py
@@ -204,7 +204,7 @@
 
     def initialize_options(self):
         build.initialize_options(self)
-        self.no_build_docs = False
+        self.no_build_docs = True
 
     def has_docs(self):
         return not self.no_build_docs