build: add gitconfig on install#35

<!--- Provide a general summary of your changes in the Title above. --> <!--- Don't worry, these comments go away when you submit! --> ## What's does this do? <!--- Does this reference any Issue #s ? If so, please link them. --> <!--- Otherwise, please provide a summary of WHY and HOW this was done. --> <!--- If needed, does this update the documentation? --> ## How has this been tested? <!--- Does this break any functionality? --> Detailed changes are in commits below.