0.2.0

Make token optional and allow specifying headers at least for enabling authentication via 'X-API-KEY' header , because initially implemented in 0.1.0 bearer auth isn't working.
Fix Query build_search_term and build_exclude_term to be compatible with Ruby < 2.4, analyzing value for 'Fixnum ' class.
Fix the gem's name in gemspec to 'fulfil-io', as registered at RubyGems.
Remove Rake version constraint from gemspec.
Add Gemfile.lock to .gitignore and remove it from git-tree - it shouldn't be stored in git for a gem.

0.1.0