Forjj segfault if contrib repo location does not exist

Created by: uggla

See log below.

[uggla@ugglalaptop bitbucket]$ rm -Rf bitbucket/ && forjj create --infra-path=bitbucket --run-plugin-debugger=bitbucket --contribs-repo=~/go/src 2>&1 | tee kevin.log
branch master, build_date 2018-07-21_22:58:28_+0200, build_commit ebbca899263e4918ed70353f51cefc902e69f10b, build_tag false.
WARNING ! main.(*Forj).ParseContext: stat /home/uggla/workspace/go/src/bitbucket/bitbucket: no such file or directory
2018/08/03 12:49:16 git init /home/uggla/workspace/go/src/bitbucket/bitbucket/.forj-workspace/deployments/production
2018/08/03 12:49:16 stdout Initialized empty Git repository in /home/uggla/workspace/go/src/bitbucket/bitbucket/.forj-workspace/deployments/production/.git/
2018/08/03 12:49:16 git init /home/uggla/workspace/go/src/bitbucket/bitbucket/.forj-workspace/deployments/dev
2018/08/03 12:49:16 stdout Initialized empty Git repository in /home/uggla/workspace/go/src/bitbucket/bitbucket/.forj-workspace/deployments/dev/.git/
2018/08/03 12:49:16 git init /home/uggla/workspace/go/src/bitbucket/bitbucket/.forj-workspace/deployments/test
2018/08/03 12:49:16 stdout Initialized empty Git repository in /home/uggla/workspace/go/src/bitbucket/bitbucket/.forj-workspace/deployments/test/.git/
2018/08/03 12:49:16 Organization : 'demoforjjprod'
2018/08/03 12:49:16 Unable to load plugin information for instance 'bitbucket'. Document not found from URLs given
WARNING ! main.(*Forj).contextDisplayed: Forjj has loaded the following context:
Forjfile model: /home/uggla/workspace/go/src/bitbucket/Forjfile
-------------------------------------

2018/08/03 12:49:16 Set default upstream application to 'bitbucket'
2018/08/03 12:49:16 CREATE: Automatic git push and forjj maintain enabled.
WARNING ! forjj/forjfile.(*Forge).Validate: Found infra data from deployment ''. This definition is ignored. Move it to your main Forjfile.
WARNING ! forjj/forjfile.(*Forge).Validate: Found infra data from deployment ''. This definition is ignored. Move it to your main Forjfile.
Validated successfully.
panic: runtime error: invalid memory address or nil pointer dereference
[signal SIGSEGV: segmentation violation code=0x1 addr=0x8 pc=0x7cbf86]

goroutine 1 [running]:
forjj/scandrivers.(*ScanDrivers).DoScanDriversObject(0xc4201a3080, 0xc4201c8ec0, 0xc4201a3080)
	/go/src/forjj/scandrivers/scan_drivers.go:99 +0x666
main.(*Forj).scanAndSetDefaults(0xb897c0, 0xc42017e150, 0x8fb86f, 0x6, 0x7721da, 0xc4200b4900)
	/go/src/forjj/drivers_options.go:482 +0x136
main.(*Forj).Create(0xb897c0, 0xc42011e5a0, 0x3)
	/go/src/forjj/create.go:122 +0x142
main.(*Forj).createAction(0xb897c0, 0x8fb80f, 0x6)
	/go/src/forjj/create.go:18 +0x40
main.(*Forj).(main.createAction)-fm(0x8fb80f, 0x6)
	/go/src/forjj/app.go:239 +0x3e
main.main()
	/go/src/forjj/forjj.go:52 +0x1ed