doc/buildman: typo 'require'

%s/require/required/

Signed-off-by: Heinrich Schuchardt <heinrich.schuchardt@canonical.com>
diff --git a/tools/buildman/buildman.rst b/tools/buildman/buildman.rst
index 924564b..07ecc5c 100644
--- a/tools/buildman/buildman.rst
+++ b/tools/buildman/buildman.rst
@@ -247,7 +247,7 @@
    section is ignored. If more than one line is provided, only the last one
    is taken.
 
-#. Make sure you have the require Python pre-requisites
+#. Make sure you have the required Python pre-requisites
 
    Buildman uses multiprocessing, Queue, shutil, StringIO, ConfigParser and
    urllib2. These should normally be available, but if you get an error like