doc: add v1.2 to the release navigation picker

Signed-off-by: David B. Kinder <david.b.kinder@intel.com>

doc/conf.py

@@ -189,10 +189,10 @@ else:
 html_context = {
    'current_version': current_version,
    'versions': ( ("latest", "/latest/"),
+                 ("1.2", "/1.2/"),
                  ("1.1", "/1.1/"),
                  ("1.0", "/1.0/"),
                  ("0.8", "/0.8/"),
-                 ("0.7", "/0.7/"),
                )
     }