fix parameters of PageMetric.new
fix error in travis with Ruby 1.8
fix test; use same ruby interpreter in test_*_cmd.rb
Revert "fix test; use same ruby interpreter in test_*_cmd.rb"

This reverts commit 96f79481eb814393b7339b285928b674545ee1a7.
Revert "fix error in travis with Ruby 1.8"

This reverts commit fe58a8ad7a1f057dcb13ee9f1b0d13b1e2cc5385.
Revert "fix parameters of PageMetric.new"

This reverts commit 106accafa880ba7be3489a08b2ac5c23fff53247.