trim trailing whitespace and insert final newline for ruby files

.editorconfig

@@ -352,6 +352,8 @@ ij_json_wrap_long_lines = false
 [{rcov,spec,rake,rails,spork,capfile,gemfile,rakefile,guardfile,isolate,vagrantfile,Puppetfile,*.jbuilder,*.rbw,*.gemspec,*.thor,*.ru,*.rb,*.rake}]
 indent_size = 2
 tab_width = 2
+trim_trailing_whitespace=true
+insert_final_newline=true
 ij_continuation_indent_size = 2
 ij_ruby_align_group_field_declarations = false
 ij_ruby_align_multiline_parameters = true