Values are not properly encoded in URLs

[rveznaver]

Hi,

For a given metric name or dimension key/value the fields are simply joined with a / instead of encoding it before, and then joining it.

Example:
A dimension with a key AwsUniqueId and value applicationelb_app/myalb/id will send a PUT request upon calling dimension_update to the URL https://api.signalfx.com/v2/dimension/AWSUniqueId/applicationelb_app/myalb/id instead of https://api.signalfx.com/v2/dimension/AWSUniqueId/applicationelb_app%2Fmyalb%2Fid.

Workaround for given example is possible by monkey patching the object instance:

import urllib.parse
import types
import signalfx

def monkeypatch_update_dimension(self, key, value, description=None,
                                 custom_properties=None, tags=None, **kwargs):
    '''monkeypatch dimension update'''
    data = {'description': description or '',
            'customProperties': custom_properties or {},
            'tags': tags or [],
            'key': key,
            'value': value}

    resp = self._put(self._u(self._DIMENSION_ENDPOINT_SUFFIX,
                             urllib.parse.quote(key, safe=''),
                             urllib.parse.quote(value, safe='')),
                     data=data, **kwargs)
    resp.raise_for_status()
    return resp.json()

def main():
    sfx = signalfx.SignalFx()
    rest = sfx.rest(args.token)
    rest.update_dimension = types.MethodType(monkeypatch_update_dimension, rest)

This only solves the use case provided in the example, but I believe the same would apply to other methods as well. I unfortunately do not have the time to write a proper pull request for all methods that would need patching, but I believe the latter should provide enough information for a fix.

I was thinking it would be more elegant to patch the _u function, but since the endpoints have slashes inside that actually need to be non-encoded, it would not really work to apply the encoding to all arguments.

Let me know if you need any more info.