Whitespace and added a note how to run the tests

--HG--
branch : distribute
extra : rebase_source : ce8146ff9d4e46e3e3b5e3a49e79debe7d260fab

DEVGUIDE.txt

@@ -6,7 +6,6 @@ Distribute is using Mercurial.
 
 Grab the code at bitbucket::
 
-
     $ hg clone https://tarek@bitbucket.org/tarek/distribute distribute
 
 If you want to work in the 0.6 branch, you have to switch to it::
@@ -24,4 +23,6 @@ If you make some changes, don't forget to:
 And remember that 0.6 is only bug fixes, and the APIs should
 be fully backward compatible with Setuptools.
 
+You can run the tests via::
 
+    $ python setup.py test