g2o 2017-07-30
g2o 2017-07-30

Closes #6027.

Signed-off-by: ilovezfs <fbd54dbbcf9e596abad4ccdc4dfc17f80ebeaee2@icloud.com>

heuermh/homebrew-science,andrewjpage/homebrew-science,pditommaso/homebrew-science