Make kitchen.text.converters.exception_to_* not swallow

general errors such as KeyboardInterrupt
Bug: https://fedorahosted.org/kitchen/ticket/9

Patch-Name: explicit_Exception_catching

kitchen2/kitchen/text/converters.py

@@ -499,7 +499,7 @@ def exception_to_unicode(exc, converters=EXCEPTION_CONVERTERS):
     for func in converters:
         try:
             msg = func(exc)
-        except:
+        except Exception:
             pass
         else:
             break
@@ -531,7 +531,7 @@ def exception_to_bytes(exc, converters=EXCEPTION_CONVERTERS):
     for func in converters:
         try:
             msg = func(exc)
-        except:
+        except Exception:
             pass
         else:
             break