[playhouse.dataset.DataSet] Cannot process column name contain "_"
Version:
- Python: 3.6.1
- peewee: 2.10.1  The problem is the "_id" suffix. DataSet relies on the introspection tools in the `playhouse.reflection` module. These tools are used to read the database and generate peewee Model definitions. There's a convention in peewee, borrowed from Django, to append "_id" to foreign key fields. So if I have a Tweet and User model, and the Tweet.author is a foreign key to a User, the column will actually be called Tweet.author_id (though the field name is "author"). This comes into play when introspecting, which does the inverse -- if it sees a column named "xxx_id", it will strip the "_id" from the field name (preserving it for the column).

I'll look into how to fix this, at any rate. d68ae11501face8f4eb6adfde82d8eda79728dc7 Thanks for the quick fix and support.   For sure, thanks for the nice reports.
Here is the test case.
```python
    def test_case_1(self):
        db = DataSet('sqlite:///:memory:')
        books = db["books"]
        books.insert(book_id="ISBN1234567")
```
It should work but report following error:

```python
Traceback (most recent call last):
... ...
  File "/Users/renweibo/PycharmProjects/DailyNovel/common/test_driver.py", line 12, in test_case_1
    books.insert(book_id="ISBN1234567")
  File "/Users/renweibo/.virtualenvs/flask1/lib/python3.6/site-packages/playhouse/dataset.py", line 219, in insert
    return self.model_class.insert(**data).execute()
  File "/Users/renweibo/.virtualenvs/flask1/lib/python3.6/site-packages/peewee.py", line 4893, in insert
    fdict.update([(cls._meta.fields[f], insert[f]) for f in insert])
  File "/Users/renweibo/.virtualenvs/flask1/lib/python3.6/site-packages/peewee.py", line 4893, in <listcomp>
    fdict.update([(cls._meta.fields[f], insert[f]) for f in insert])
KeyError: 'book_id'
```