Methodname needs to be str, not bin

[mbr0wn]

OK, #44 fixed blobs, but it broke mprpc in a different way 😢

According to the spec, the method name needs to be a UTF-8 string, not a binary object. If the client is running Python 2, the default string type is binary, and thus msgpack-python will serialize it as such when use_bin_type is set.

I'm not a Cython expert, but it seems like the issue is here:

mprpc/mprpc/client.pyx

Lines 123 to 128 in a7a05e6

	def call(self, str method, *args):
	"""Calls a RPC method.
	:param str method: Method name.
	:param args: Method arguments.
	"""

The type of method is str, but that's an ambiguous type across Python version boundaries. In Python 2, it'll be binary, in Python 3, it'll be Unicode.

[mbr0wn]

#45 is a proposed fix.