google-api-python-client Version Check is broken
Hi All, I cannot use io.gbq due to an issue with the version check of the installed google library.

```
>>> pkg_resources.get_distribution('google-api-python-client').version
'1.2'
```

The [offending line](https://github.com/pydata/pandas/blob/master/pandas/io/gbq.py#L29) executes the version check as follows:

```
>>> pkg_resources.get_distribution('google-api-python-client').version < '1.2.0'
True
```

but

```
>>> pkg_resources.get_distribution('google-api-python-client').version < '1.2'
False
```
