Reading tensor needs file to be opened in writeable mode

[asfimport]

Tensors written in OSFile, while reading needs to file to be opened in writeable mode. read_tensor() is not working with any mode of file using OSFile. It works only with mem_mapped files(that too in 'r+w' mode)

"IOError: only valid on writeable files"

Reporter: Vaishal Shah
Assignee: Philipp Moritz / @pcmoritz

_{Note: This issue was originally created as ARROW-1097. Please see the migration documentation for further details.}

[asfimport]

Wes McKinney / @wesm:
This was fixed in bfe15db