Make several testing stub methods tz aware

[amureki]

Description

Real Closeio API during lead and task creation provides datetimes with TZ data, so to be accurate we need to update our testing stub.

How to test

You can create a task and will see the response you'll get:

In [13]: closeio.create_task(lead_id='YOUR_LEAD_ID', assigned_to='YOUR_USER_ID', text='PRtest')
Out[13]:
{'_type': 'lead',
 'assigned_to': 'HIDDEN',
 'assigned_to_name': 'HIDDEN',
 'contact_id': None,
 'contact_name': None,
 'created_by': 'HIDDEN',
 'created_by_name': 'HIDDEN',
 'date': datetime.date(2018, 5, 31),
 'date_created': datetime.datetime(2018, 5, 31, 15, 4, 25, 274000, tzinfo=tzutc()),
 'date_updated': datetime.datetime(2018, 5, 31, 15, 4, 25, 274000, tzinfo=tzutc()),
 'due_date': None,
 'id': 'HIDDEN',
 'is_complete': False,
 'is_dateless': True,
 'lead_id': 'HIDDEN',
 'lead_name': 'HIDDEN',
 'object_id': None,
 'object_type': None,
 'organization_id': 'HIDDEN',
 'text': 'PRtest',
 'updated_by': 'HIDDEN',
 'updated_by_name': 'HIDDEN',
 'view': 'inbox'}

[codecov[bot]]

Codecov Report

Merging #125 into master will not change coverage. The diff coverage is 0%.

@@           Coverage Diff           @@
##           master     #125   +/-   ##
=======================================
  Coverage   41.22%   41.22%           
=======================================
  Files           9        9           
  Lines         781      781           
=======================================
  Hits          322      322           
  Misses        459      459

Impacted Files	Coverage Δ
closeio/contrib/testing_stub.py	0% <0%> (ø)	:arrow_up:

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[amureki]

@codingjoe @mostafa-anm many thanks! ✨