Start adding example new logic tests

`ckan.model.repo.rebuild_db()` is freezing for me when I run these tests.

The command I'm running is:

    nosetests --ckan --with-pylons=test-custom.ini --nologcapture --nocapture ckan/new_tests

(I have a `test-custom.ini` file that wraps `test-core.ini`, all it does is set the solr url).

The first time I run the command I get the exception below. After that, running the tests will get as far as printing `Rebuilding db` but never print `db rebuilt`

If I drop and recreate the test db, then I can run the tests and get the exception again:

    sudo -u postgres dropdb ckan_test; sudo -u postgres createdb -O ckan_default ckan_test -E utf-8;

Exception:

```
Traceback (most recent call last):
  File "/home/seanh/.virtualenvs/ckan/local/lib/python2.7/site-packages/nose/case.py", line 197, in runTest
    self.test(*self.arg)
  File "/home/seanh/Projects/ckan/ckan/ckan/new_tests/logic/action/test_update.py", line 33, in test_user_update
    user = logic.call_action('user_create', **test_data.FRED)
  File "/home/seanh/Projects/ckan/ckan/ckan/new_tests/logic/__init__.py", line 27, in call_action
    return logic.get_action(action_name)(context=context, data_dict=kwargs)
  File "/home/seanh/Projects/ckan/ckan/ckan/logic/__init__.py", line 329, in wrapped
    return _action(context, data_dict, **kw)
  File "/home/seanh/Projects/ckan/ckan/ckan/logic/action/create.py", line 785, in user_create
    data, errors = _validate(data_dict, schema, context)
  File "/home/seanh/Projects/ckan/ckan/ckan/lib/navl/dictization_functions.py", line 229, in validate
    converted_data, errors = _validate(flattened, schema, context)
  File "/home/seanh/Projects/ckan/ckan/ckan/lib/navl/dictization_functions.py", line 290, in _validate
    convert(converter, key, converted_data, errors, context)
  File "/home/seanh/Projects/ckan/ckan/ckan/lib/navl/dictization_functions.py", line 187, in convert
    converter(key, converted_data, errors, context)
  File "/home/seanh/Projects/ckan/ckan/ckan/logic/validators.py", line 488, in user_name_validator
    result = query.first()
  File "/home/seanh/.virtualenvs/ckan/local/lib/python2.7/site-packages/sqlalchemy/orm/query.py", line 2156, in first
    ret = list(self[0:1])
  File "/home/seanh/.virtualenvs/ckan/local/lib/python2.7/site-packages/sqlalchemy/orm/query.py", line 2023, in __getitem__
    return list(res)
  File "/home/seanh/.virtualenvs/ckan/local/lib/python2.7/site-packages/sqlalchemy/orm/query.py", line 2227, in __iter__
    return self._execute_and_instances(context)
  File "/home/seanh/.virtualenvs/ckan/local/lib/python2.7/site-packages/sqlalchemy/orm/query.py", line 2242, in _execute_and_instances
    result = conn.execute(querycontext.statement, self._params)
  File "/home/seanh/.virtualenvs/ckan/local/lib/python2.7/site-packages/sqlalchemy/engine/base.py", line 1449, in execute
    params)
  File "/home/seanh/.virtualenvs/ckan/local/lib/python2.7/site-packages/sqlalchemy/engine/base.py", line 1584, in _execute_clauseelement
    compiled_sql, distilled_params
  File "/home/seanh/.virtualenvs/ckan/local/lib/python2.7/site-packages/sqlalchemy/engine/base.py", line 1698, in _execute_context
    context)
  File "/home/seanh/.virtualenvs/ckan/local/lib/python2.7/site-packages/sqlalchemy/engine/base.py", line 1691, in _execute_context
    context)
  File "/home/seanh/.virtualenvs/ckan/local/lib/python2.7/site-packages/sqlalchemy/engine/default.py", line 331, in do_execute
    cursor.execute(statement, parameters)
InternalError: (InternalError) current transaction is aborted, commands ignored until end of transaction block
 'SELECT "user".name AS user_name \nFROM "user" \nWHERE "user".name = %(name_1)s \n LIMIT %(param_1)s' {'name_1': 'fred', 'param_1': 1}
```