Feature request: pandas.Series.query()
I would like to request a `pandas.Series.query()` method that works identically to [`pandas.DataFrame.query()`](https://pandas.pydata.org/pandas-docs/stable/generated/pandas.DataFrame.query.html).

I have a large multi-indexed series that I would like to split into training and testing data for an ML research project. A minimal working example would be:
```python
import pandas as pd

years = range(2002, 2018)
fields = range(1, 5)

index = pd.MultiIndex.from_product(
    [years, fields], names=['year', 'field'])

series = pd.Series(index=index)
```
What I would like to be able to do is split this series into 2010 data and _not_ 2010 data. Accessing 2010 data is very easy:
```python
test_data = series[2010]
```
Accessing _not_ 2010 data is very hard. This is the shortest method I've found so far:
```python
train_data = series.to_frame().query('year != 2010')[0]
```
Since `pandas.Series` doesn't support `query()`, I have to convert it to a DataFrame and then back into a Series. Is there any reason why `pandas.Series` doesn't support `query` directly?