Adjusted README's testing instructions.

README.rst

@@ -65,7 +65,7 @@ nose_ works great! ::
 
     pip install nose
     cd pystache
-    nosetests --with-doctest --doctest-extension=rst
+    nosetests
 
 To include tests from the mustache spec_ in your test runs: ::
 
@@ -73,6 +73,10 @@ To include tests from the mustache spec_ in your test runs: ::
     git submodule update
     nosetests -i spec
 
+To run all available tests:
+
+    nosetests --with-doctest --doctest-extension=rst -i spec
+
 
 Mailing List
 ==================