Fix the renderable behavior of Git

Closes #283

Signed-off-by: Ian Bell <ian.h.bell@gmail.com>

dev/buildbot/master/master.cfg

@@ -232,19 +232,11 @@ def gitModeInput(props):
         return 'full'
     else:
         return 'incremental'
-
-@properties.renderer
-def gitMethodInput(props):
-    """ If we are doing a full clean, this will tell it to clobber all the files """
-    if props.getProperty('fullclean', default = False):
-        return 'clobber'
-    else:
-        return None
 
 # A centralised method to provide the objects with some presets
 def getBaseFactory(gitMode = 'incremental'):
     factory = BuildFactory()
-    factory.addStep(Git(repourl='git://github.com/CoolProp/CoolProp', mode=gitModeInput, method = gitMethodInput, submodules = True, progress=True, haltOnFailure = True))
+    factory.addStep(Git(repourl='git://github.com/CoolProp/CoolProp', mode=gitModeInput, method = 'fresh', submodules = True, progress=True, haltOnFailure = True))
     return factory
 
 def docActivateCmd():