Allow for custom deploy folder locations

[crueter]

Is your feature request related to a problem? Please describe.
When writing C++ robot projects I generally prefer to move everything higher up in the root hierarchy. This results in all cpp/h files being placed in src, and my deploy folder being placed in the root. However, PathPlanner currently forces everything into src/main/deploy, which is not ideal in this case.

Describe the solution you'd like
If src/main doesn't exist, prompt the user to select a custom deploy location.

Additional context
Add any other context or screenshots about the feature request here.

[crueter]

(build.gradle could also be read)