Add frame and cmap to the colorbar parameters list (#709)

Author: willschlitzer

pygmt/base_plotting.py

@@ -179,6 +179,9 @@ def colorbar(self, **kwargs):
 
         Parameters
         ----------
+        frame : str or list
+            Set color bar boundary frame, labels, and axes attributes.
+        {CPT}
         position : str
             ``[g|j|J|n|x]refpoint[+wlength[/width]][+e[b|f][length]][+h|v]
             [+jjustify][+m[a|c|l|u]][+n[txt]][+odx[/dy]]``. Defines the