Updated installation.md (#118)
Updated installation.md (#118)

Improved Linux section of installation.md
Removed a troubleshooting tip that was (almost) always required and instead incorporated it in the cloning command. 
Added a command to change directory to the one which is recommended.
saurabhshri/sample-platform,satyammittal/sample-platform,canihavesomecoffee/sample-platform,saurabhshri/sample-platform,canihavesomecoffee/sample-platform,satyammittal/sample-platform,canihavesomecoffee/sample-platform,satyammittal/sample-platform,saurabhshri/sample-platform,canihavesomecoffee/sample-platform,saurabhshri/sample-platform,satyammittal/sample-platform