Use existing client in List, Find, etc.

Instead of calling `default_client()` for each of those class methods, use a
new method, `get_existing_client`, which gets if a user has setup a new api
client with `configure`.

Solves #13.

Author: BryceStevenWilley

.gitignore

@@ -2,4 +2,5 @@
 dist/
 build/
 cloudconvert.egg-info/
-*.egg
+*.egg
+**/__pycache__

cloudconvert/cloudconvertrestclient.py

@@ -245,6 +245,11 @@ def default_client():
 
     return __client__
 
+def get_existing_client():
+    """Gets an already created client if there is one, None otherwise."""
+    global __client__
+    return __client__
+
 
 def set_config(options=None, **config):
     """Create new default api object with given configuration

cloudconvert/resource.py

@@ -1,7 +1,7 @@
 import uuid
 import urllib
 import cloudconvert.utils as util
-from cloudconvert.cloudconvertrestclient import default_client
+from cloudconvert.cloudconvertrestclient import default_client, get_existing_client
 
 
 class Resource(object):
@@ -114,7 +114,7 @@ def find(cls, id):
         Usage::
             >>> job = Job.find("s9fsf9-s9f9sf9s-ggfgf9-fg9fg")
         """
-        api_client = default_client()
+        api_client = get_existing_client() or default_client()
 
         url = util.join_url(cls.path, str(id))
         res = api_client.get(url)
@@ -134,7 +134,7 @@ def all(cls, params=None):
         Usage::
             >>> tasks_list = tasks.all({'status': 'waiting'})
         """
-        api_client = default_client()
+        api_client = get_existing_client() or default_client()
 
         if params is None:
             url = cls.path
@@ -165,7 +165,7 @@ def create(cls, operation=None, payload={}):
             >>> task.create(name=TASK_NAME) # return newly created task
         """
 
-        api_client = default_client()
+        api_client = get_existing_client() or default_client()
         url = util.join_url('v2', operation or '')
         res = api_client.post(url, payload, headers={})
 
@@ -182,7 +182,7 @@ def wait(cls, id):
         Usage::
             >>> job = job.wait("s9fsf9-s9f9sf9s-ggfgf9-fg9fg")
         """
-        api_client = default_client()
+        api_client = get_existing_client() or default_client()
 
         url = util.join_url(cls.path, str(id))
         res = api_client.get_sync(url)
@@ -199,7 +199,7 @@ def show(cls, id):
         Usage::
             >>> job = Job.show("s9fsf9-s9f9sf9s-ggfgf9-fg9fg")
         """
-        api_client = default_client()
+        api_client = get_existing_client() or default_client()
         url = util.join_url(cls.path, str(id))
         res = api_client.get(url)
         try:
@@ -215,7 +215,7 @@ def delete(cls, id):
         Usage::
             >>> Task.delete(TASK_ID)
         """
-        api_client = default_client()
+        api_client = get_existing_client() or default_client()
         url = util.join_url(cls.path, str(id))
         api_resource = Resource()
         new_attributes = api_client.delete(url)