Start testing cloud convert API

Handled several issues here:
1. The environment variables are wrongly hardcoded, and you can't
  use the alternative of providing your own API Keys from elsewhere.
  See cloudconvert/cloudconvert-python#13 and
  cloudconvert/cloudconvert-python#24. Will
  need to fix this to be able to run in docassemble.
2. Imports/uploading files: you need to follow this example: https://github.com/cloudconvert/cloudconvert-python#uploading-files
3. The output document somehow has more validation errors, but still opens fine in office.com.
  For some reason, the office converter doesn't convert from RTF to DOCX,
  so it uses the libreoffice converter instead, which generates all of those
  validation errors. Will just have to go with it, as long as some more obscure choices work
  in all of the testing files (drive, office 365, desktop office, and libreoffice).

  Details: combining from GDocs: 9 errors:
  * ExceptionError: Inner exception: 'a' is an undeclared prefix.
  * several Sch_AttributeValueDataTypeDetaileds, with in:w and in:hanging with invalid values (0.0 or 115.0 not valid Int16)

  from combining from cloudconvertAPI: 635 errors
  * mostly Sch_UnexpectedElementContentExpectingComplex: has unexpecetd child element 'main:b'
  * Sch_MissRequiredAttribute: the required attribute 'val' is missing
  * Sch_AttributeValueDataTypeDetailed: the attribute main:val has invalid value 'end' (sometimes 'start')

Resources to use when picking back up:
* https://sandbox.cloudconvert.com/dashboard/jobs#
* https://cloudconvert.com/api/v2/jobs/builder#
* https://cloudconvert.com/api/v2/import#import-url-tasks

test_cloudconvert.py

@@ -0,0 +1,81 @@
+import cloudconvert
+from docxtpl import DocxTemplate, RichText
+import os
+
+def merge(all_docs, out_name):
+  tpl = DocxTemplate('docassemble/tclpgoogledocsmerger/data/templates/ClausesTemplate_fixed.docx')
+  subdocs = []
+  for doc in all_docs:
+    link = RichText('Online resources at no where')
+    subdocs.append((doc, 'mydate', link, tpl.new_subdoc(doc)))
+
+  context = {
+    'mysubdoc': subdocs,
+    'today_date': 'mydate_global',
+    'tags_with_rows': [],
+  }
+
+  tpl.render(context)
+  tpl.save(out_name) 
+  return
+
+def use_cloudconvert(in_name):
+  cloudconvert.default() 
+
+  job = cloudconvert.Job.create(payload={"tasks": {
+    'import-my-file': {
+      'operation': 'import/upload',
+    },
+    'convert-my-file': {
+      'operation': 'convert',
+      'input': 'import-my-file',
+      'input_format': 'docx',
+      'output_format': 'rtf',
+      'engine': 'office',
+    },
+    'convert-my-file-back': {
+      'operation': 'convert',
+      'input': 'convert-my-file',
+      'input_format': 'rtf',
+      'output_format': 'docx',
+     # 'engine': 'office',
+    },
+    'export-my-file': {
+      'operation': 'export/url',
+      'input': 'convert-my-file-back'
+    }
+    },
+    "tag": "jobbuilder",
+  })
+
+  upload_task_id = job['tasks'][0]['id']
+  upload_task = cloudconvert.Task.find(id=upload_task_id)
+  res = cloudconvert.Task.upload(file_name=in_name, task=upload_task)
+  print(f'Task.upload res: {res}')
+  res = cloudconvert.Task.find(id=upload_task_id)
+  print(f'Task.find res: {res}')
+  job = cloudconvert.Job.wait(id=job['id'])
+
+  if 'tasks' not in job:
+    print(f'failed!: {job}')
+    return
+
+
+  for task in job["tasks"]:
+    if task.get("name") == "export-my-file" and task.get("status") == "finished":
+      export_task = task
+      break
+
+  file_info = export_task.get("result").get("files")[0]
+  cloudconvert.download(filename='post-' + file_info['filename'], url=file_info['url'])
+
+
+if __name__ == '__main__':
+  merge(['aatmay.docx', 'robyn.docx', 'elsie.docx', 'aiden.docx'], 'pre-convert.docx')
+  use_cloudconvert('aatmay.docx')
+  use_cloudconvert('robyn.docx')
+  use_cloudconvert('elsie.docx')
+  use_cloudconvert('aiden.docx')
+  merge(['post-aatmay.docx', 'post-robyn.docx', 'post-elsie.docx', 'post-aiden.docx'], 'post-convert.docx')
+
+