Error installing ruby on rails

I am trying to install ruby on rails with this link

But getting error. When I ran this rvm install 2.3.1
I get this error

     mkdir: cannot create directory ‘/usr/local/rvm/log/1467720951_ruby-2.3.1’: Permission denied
tee: /usr/local/rvm/log/1467720951_ruby-2.3.1/update_system.log: No such file or directory

     Error running 'requirements_debian_update_system ruby-2.3.1',
    showing last 15 lines of /usr/local/rvm/log/1467720651_ruby-2.3.1/update_system.log
    tail: cannot open ‘/usr/local/rvm/log/1467720651_ruby-2.3.1/update_system.log’ for reading: No such file or directory
    Requirements installation failed with status: 1.<br/>
When i ran curl -sSL https://get.rvm.io | bash -s stable <br/>
so it was install on /usr/local/rvm