[fixup] Fix zc.recipe.egg tests

Fixup [feat] Add dependencies in __buildout_signature__

Some zc.recipe.egg tests were never adapted to zc.buildout 3.0.1
now using pip and wheel in addition to setuptools.

zc.recipe.egg_/src/zc/recipe/egg/api.rst

@@ -104,7 +104,7 @@ computed by the egg recipe by looking at .installed.cfg:
     <BLANKLINE>
     [sample-part]
     __buildout_installed__ = 
-    __buildout_signature__ = sample-... setuptools-... zc.buildout-... zc.recipe.egg-...
+    __buildout_signature__ = pip-... sample-... setuptools-... zc.buildout-... zc.recipe.egg-...
     _b = /sample-buildout/bin
     _d = /sample-buildout/develop-eggs
     _e = /sample-buildout/eggs