[dev] simplify requires

lib/refrepo.rb

lib/refrepo/gen/oar-properties.rb

lib/refrepo/gen/puppet/bindg5k.rb

lib/refrepo/gen/puppet/conmang5k.rb

lib/refrepo/gen/puppet/dhcpg5k.rb

lib/refrepo/gen/puppet/kadeployg5k.rb

lib/refrepo/gen/puppet/kavlang5k.rb

lib/refrepo/gen/puppet/lanpowerg5k.rb

lib/refrepo/gen/reference-api.rb

lib/refrepo/gen/wiki/generators/hardware.rb

lib/refrepo/gen/wiki/generators/oar_properties.rb

lib/refrepo/gen/wiki/generators/site_hardware.rb

lib/refrepo/gen/wiki/generators/site_network.rb

lib/refrepo/gen/wiki/mw_utils.rb

lib/refrepo/gen/wiki/wiki_generator.rb

lib/refrepo/input_loader.rb

lib/refrepo/valid/homogeneity.rb

lib/refrepo/valid/input/duplicates.rb

lib/refrepo/valid/input/lib/schema_validator.rb

lib/refrepo/valid/input/schema.rb