Remove -f / --file option from OHAI. This option was useful when developing OHAI plugins in OHAI 6 but not anymore in OHAI 7. The way to get a similar functionality is to run:

ohai -d .
=> get all the attributes by running the plugins in the current directory
ohai -d . my_attribute_name
=> only to get the attribute you're developing
Merge pull request #268 from opscode/OC-10958

Remove -f / --file option from OHAI.