Fix yet another UnicodeDecode issue with Python 2

Author: dan-blanchard

drmaa/helpers.py

@@ -200,8 +200,13 @@ def __init__(self, name):
         self.name = name
 
     def __set__(self, instance, value):
-        v = ["{0}={1}".format(k, v).encode(ENCODING) for (k, v) in
-             value.items()]
+        v = []
+        for k, v in value.items():
+            if isinstance(k, bytes):
+                k = k.decode(ENCODING)
+            if isinstance(v, bytes):
+                v = v.decode(ENCODING)
+            v.append("{0}={1}".format(k, v).encode(ENCODING))
         c(drmaa_set_vector_attribute, instance, self.name,
           string_vector(v))