I had the same issue, and I was able to fix it. However, my exact solution might be useless for you. I had oh-my-zsh installed. It looks like during installation, it was trying to mimic my .bashrc files and it screwed PATH variable for me. Here's the line I had trouble with:
export PATH="/home/alexander/.rvm/gems/ruby-2.1.1@security/bin:/home/alexander/.rvm/gems/ruby-2.1.1@global/bin:/home/alexander/.rvm/rubies/ruby-2.1.1/bin:/home/alexander/.nvm/v0.10.25/bin:/home/alexander/work/gc-sdk/google-cloud-sdk/bin:/usr/lib/lightdm/lightdm:/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:/usr/games:/home/alexander/.rvm/bin"
So, you need to verify if your PATH variable isn't tempered with. And you need to let RVM configure it for you. Both these things can be done with a simple command in your terminal (assuming you have RVM installed):
rvm get stable --auto-dotfiles
Also, there're couple of issues created on GitHub. The common advice is to use command from above and switch your terminal to login shell.
Hope it helps!