Feature to read csv from hdfs:// URL
When running pandas in AWS, The following works perfectly fine:
```python
pd.read_csv("s3://mybucket/data.csv")
```
But running the following, does not:
```python
pd.read_csv("hdfs:///tmp/data.csv")
```

It would be a good user experience to allow for the hdfs:// schema too similar to how http, ftp, s3, and file are valid schemas right now.