add support for AWS Organizations

endpoints covers so far:
- create_organization
- describe_organization
- create_account
- describe_account
- list_accounts

all tests passing.
could use some advise from maintaners.

tests/test_organizations/object_syntax.py

@@ -0,0 +1,24 @@
+"""
+Temporary functions for checking object structures while specing out
+models.  This module will go away.
+"""
+
+import yaml
+import moto
+from moto import organizations as orgs
+
+
+# utils
+print(orgs.utils.make_random_org_id())
+print(orgs.utils.make_random_root_id())
+print(orgs.utils.make_random_account_id())
+print(orgs.utils.make_random_create_account_id())
+
+# models
+my_org = orgs.models.FakeOrganization(feature_set = 'ALL')
+print(yaml.dump(my_org._describe()))
+#assert False
+
+my_account = orgs.models.FakeAccount(my_org, AccountName='blee01', Email='blee01@moto-example.org')
+print(yaml.dump(my_account))
+#assert False