using uplink.Url results in an AttributeError

[cognifloyd]

Describe the bug
Attempting to use uplink.Url results in an AttributeError.

...
    return self._check_async_results(future_response.location)
  File "/home/cognifloyd/v/st2/lib/python2.7/site-packages/uplink/builder.py", line 99, in __call__
    self._request_definition.define_request(request_builder, args, kwargs)
  File "/home/cognifloyd/v/st2/lib/python2.7/site-packages/uplink/commands.py", line 271, in define_request
    request_builder.url = request_builder.url.build()
AttributeError: 'str' object has no attribute 'build'

To Reproduce
Use uplink.Url as an argument and provide a string with a full URL.

Expected behavior
A clear and concise description of what you expected to happen.
No error.

Additional context
It looks like

• commands.py line 265: request_builder.Url is set to an instance of uplink.utils.URIBuilder
• commands.py line 267: eventually calls uplink.Url._modify_request()
  • arguments.py line 682: replace request_builder.Url with the final string
• commands.py line 271: calls request_builder.url.build() assuming that it is still a URIBuilder instance.

uplink/uplink/commands.py

Lines 263 to 271 in 8483dcc

	def define_request(self, request_builder, func_args, func_kwargs):
	request_builder.method = self._method
	request_builder.url = utils.URIBuilder(self._uri)
	request_builder.return_type = self._return_type
	self._argument_handler.handle_call(
	request_builder, func_args, func_kwargs
	)
	self._method_handler.handle_builder(request_builder)
	request_builder.url = request_builder.url.build()

uplink/uplink/arguments.py

Lines 680 to 682 in 0d29483

	def _modify_request(cls, request_builder, value):
	"""Updates request url."""
	request_builder.url = value

So, maybe what's needed is:

def define_request(...):
    ...
    self._argument...
    self._method...
    if isinstance(request_builder.url, utils.URIBuilder):
        request_builder.url = request_builder.url.build() 

[cognifloyd]

I just tested, and my recommended fix does work. I'll submit a PR momentarily. I don't know if there's a better way to fix this.