Install gem without ri-documentaions

Summary:
-------
During Gem installation skip the ri and Rdoc installation process; Create a .gemrc file from home directory and paste the following code and save.

Step 1:
-------
Open terminal create .gemrc

$ touch .gemrc

Step 2:
-------
Add the following line in that file , then save and close the file. Start install gem without any RDocs

gem: --no-ri --no-rdoc