upgrade cross-spawn dependency

[sandeepkasera]

This PR upgrades the cross-spawn from version 5.0.1 to 7.0.6.

##Reason for Upgrade
Versions of the package cross-spawn before 7.0.5 are vulnerable to Regular Expression Denial of Service (ReDoS) due to
improper input sanitization. An attacker can increase the CPU usage and crash the program by crafting a very large and well
crafted string.

##Changes Made
Updated package.json

##Linked Issues
Fixes #167

[mgagliardo91]

Can we get this in so we can avoid overriding the cross-spawn dep?

[Tzahile]

@sandeepkasera I got approved, please push it
(or someone from the contributors @mgagliardo91 @serhii-boiko )

[sandeepkasera]

@Tzahile I do not have the necessary permissions to merge this pull request.

[serlight1]

Can anybody merge this MR? It's really necessary to avoid ReDoS

[kevinfmanning]

Can this ACTUALLY get reviewed/merged?