Add support for slapos.buildout >= 3.0.1+slapos001

zc.buildout >= 3.0.0 depends on pip and wheel as well

slapos/rebootstrap/bootstrap.py

@@ -10,7 +10,7 @@ class FakeSysExecutable(object):
 
 def get_distributions():
   from pkg_resources import get_distribution
-  distributions = ['setuptools', 'zc.buildout']
+  distributions = ['setuptools', 'zc.buildout', 'wheel', 'pip']
   try:
     import slapos.libnetworkcache
   except ImportError: