switch to latest slimerJS with headless firefox

screenless/bureau/bureau.py

@@ -149,11 +149,10 @@ class Bureau(object):
         self.api = {}
 
         modpath = os.path.dirname(__file__)
-        xvfb = "xvfb-run"
         slimerjs = os.path.join(modpath, "..", "lib", "slimerjs", "slimerjs")
         renderer = os.path.join(modpath, "..", "slimerjs", "rasterize.js")
         self.slimerjs = os.path.abspath(slimerjs)
-        self.html2pdf = xvfb + " " + self.slimerjs + " " + \
+        self.html2pdf = self.slimerjs + " --headless " + \
                         os.path.abspath(renderer) + " "
         mypath = inspect.getfile(self.__class__)
         self.mdir = os.path.dirname(mypath)