[enh] update dev requirements

requirements-dev.txt

@@ -3,8 +3,8 @@ mock==2.0.0
 nose2[coverage-plugin]
 pep8==1.7.0
 plone.testing==5.0.0
-robotframework-selenium2library==1.7.4
+robotframework-selenium2library==1.8.0
 robotsuite==1.7.0
-transifex-client==0.11
+transifex-client==0.12.2
 unittest2==1.1.0
-zope.testrunner==4.4.10
+zope.testrunner==4.5.1