issue-67: Create storage_lsr sub-directory under module_utils and move size.py there

#67
Have to rename a couple of imports to handle this case.
Another issue is that python 2.x does not find the module unless
it has an `__init__.py` in the `storage_lsr/` sub-directory.

Author: richm

library/bsize.py

@@ -52,7 +52,7 @@
 '''
 
 from ansible.module_utils.basic import AnsibleModule
-from ansible.module_utils.size import Size
+from ansible.module_utils.storage_lsr.size import Size
 
 def run_module():
     # available arguments/parameters that a user can pass

library/find_unused_disk.py

@@ -64,7 +64,7 @@
 import re
 
 from ansible.module_utils.basic import AnsibleModule
-from ansible.module_utils.size import Size
+from ansible.module_utils.storage_lsr.size import Size
 
 
 SYS_CLASS_BLOCK = "/sys/class/block/"

module_utils/storage_lsr/__init__.py

@@ -1,6 +1,6 @@
 import pytest
 
-from size import Size
+from storage_lsr.size import Size
 
 def test_bsize():
     # check failure on incorrect string