Pin pkginfo to 1.4.2.

Latest twine needs `pkginfo>=1.4.2`.
A few more packages are pulled in.
Updated zc.buildout to latest.

buildout.cfg

@@ -24,15 +24,17 @@ bleach = 2.1.2
 certifi = 2018.1.18
 collective.recipe.sphinxbuilder = 1.0
 colorama = 0.3.9
+CommonMark = 0.7.5
 docutils = 0.14
+future = 0.16.0
 html5lib = 1.0.1
 idna = 2.6
 imagesize = 1.0.0
 Jinja2 = 2.10
 MarkupSafe = 1.0
 martian = 1.1
 packaging = 17.1
-pkginfo = 1.4.1
+pkginfo = 1.4.2
 Pygments = 2.2.0
 pyparsing = 2.2.0
 pytz = 2018.3
@@ -48,7 +50,7 @@ typing = 3.6.4
 urllib3 = 1.22
 webencodings = 0.5.1
 z3c.testsetup = 0.8.4
-zc.buildout = 2.11.1
+zc.buildout = 2.11.2
 zc.recipe.egg = 2.0.5
 zc.recipe.testrunner = 2.0.0
 zope.exceptions = 4.2.0