File.write accepts a fourth optional argument

Previous fake File.write did not accept the valid fourth argument
`open_args`.
This commit should provide a such possibility.
I do not certify correct behavior for all cases, but at least it won’t
raise a useless exception and will extends the fakers compatibility
Merge branch 'fix/file-write-openargs'

* fix/file-write-openargs:
  File.write accepts a fourth optional argument
Fix rubocop violations added in #262.