"RVM is not a function"?

Summary:
-------
Make sure RVM should be a function.

Step 1:
-------
After installation of rvm. We need to add the add the following source to .baserc file.

$ gedit  ~/.bashrc

Step 2:
-------
Add the following line at the end of file

[[ -s "$HOME/.rvm/scripts/rvm" ]] && source "$HOME/.rvm/scripts/rvm"

save and close the file

Step 3:
-------
check rvm is a funtion

$ type rvm | head -n 1