Made tests independent of distribute version.

Replaced the fixed distribute version number with the currently valid one by
just asking for the current version and inserting that in the various spots we
need it in this testfile

src/zc/buildout/repeatable.txt

@@ -236,6 +236,13 @@ Since buildout 2.0, the functionality of the `buildout-versions
 <http://packages.python.org/buildout-versions/>`_ extension is part of
 buildout itself. This makes reporting and managing versions easier.
 
+Buildout picks a version for distribute and for the tests, we need to grab the
+version number:
+
+    >>> import pkg_resources
+    >>> req = pkg_resources.Requirement.parse('distribute')
+    >>> distribute_version = pkg_resources.working_set.find(req).version
+
 If you set the ``show-picked-versions`` option, buildout will print
 versions it picked at the end of its run:
 
@@ -270,12 +277,12 @@ When everything is pinned, no output is generated:
     ... show-picked-versions = true
     ...
     ... [versions]
-    ... distribute = 0.6.35
+    ... distribute = %s
     ... spam = 2
     ...
     ... [foo]
     ... recipe = spam
-    ... ''' % join('recipe', 'dist'))
+    ... ''' % (join('recipe', 'dist'), distribute_version))
     >>> print_(system(buildout), end='') # doctest: +ELLIPSIS
     Updating foo.
     recipe v2
@@ -294,12 +301,12 @@ and case differences won't impact the pinning:
     ... show-picked-versions = true
     ...
     ... [versions]
-    ... distriBUTE = 0.6.35
+    ... distriBUTE = %s
     ... Spam = 2
     ...
     ... [foo]
     ... recipe = spam
-    ... ''' % join('recipe', 'dist'))
+    ... ''' % (join('recipe', 'dist'), distribute_version))
     >>> print_(system(buildout), end='') # doctest: +ELLIPSIS
     Updating foo.
     recipe v2
@@ -311,9 +318,9 @@ extending from that versions file:
     >>> write('my_versions.cfg',
     ... '''
     ... [versions]
-    ... distribute = 0.6.35
+    ... distribute = %s
     ... spam = 2
-    ... ''')
+    ... ''' % distribute_version)
     >>> write('buildout.cfg',
     ... '''
     ... [buildout]
@@ -336,8 +343,8 @@ at the end.
     >>> write('my_versions.cfg',
     ... '''
     ... [versions]
-    ... distribute = 0.6.35
-    ... ''')
+    ... distribute = %s
+    ... ''' % distribute_version)
     >>> write('buildout.cfg',
     ... '''
     ... [buildout]
@@ -377,8 +384,8 @@ printing them to the console):
     >>> write('my_versions.cfg',
     ... '''
     ... [versions]
-    ... distribute = 0.6.35
-    ... ''')
+    ... distribute = %s
+    ... ''' % distribute_version)
     >>> write('buildout.cfg',
     ... '''
     ... [buildout]