Use user home path `HOME_PATH` or `TEMP_PATH` instead of somewhere inside the Ruby gem directories about bipm-data-importer

[webdev778]

Duplicate of #38

The logic as of now is that:

1. If the directory isn't writable, it falls back to homedir:

   bipm-data-importer/lib/bipm/data/outcomes.rb

   Line 46 in d97f398

   elsif !File.writable?(File.dirname(file_path))

2. Otherwise, it's possible to override a path with an attr_writer provided. Since the API is for a programmer to browse the dataset, he can simply use Bipm::Data::Outcomes.file_path = "/tmp/my_bipm_data" before executing the rest

[ronaldtse]

Thank you for the clarification, indeed it would work. Closing.