Merge pull request #949: io: Split io.py into smaller files under new io/

Author: victorlin

augur/io.py

@@ -0,0 +1,8 @@
+"""Interfaces for reading and writing data also known as input/output (I/O)
+"""
+
+from .file import *
+from .metadata import *
+from .print import *
+from .sequences import *
+from .vcf import *