Replace multierror

[derom]

This PR addresses #1482

Here is the changes in output.

Previous output:

ERRO[0000] Hit multiple errors:
Hit multiple errors:
exit status 1 

New output:

ERRO[0000] 1 error occurred:
	* exit status 1

or more detailed example
Previous output:

ERRO[0000] Module /<basePath>/bastion/storage has finished with an error: Hit multiple errors:
Hit multiple errors:
exit status 1  prefix=[/<basePath>/bastion/storage] 
ERRO[0000] Dependency /<basePath>/bastion/storage of module /<basePath>/bastion/compute just finished with an error. Module /<basePath>/bastion/compute will have to return an error too.  prefix=[/<basePath>/bastion/compute] 
ERRO[0000] Module /<basePath>/bastion/compute has finished with an error: Cannot process module Module /<basePath>/bastion/compute (excluded: false, dependencies: [/<basePath>/bastion/storage]) because one of its dependencies, Module /<basePath>/bastion/storage (excluded: false, dependencies: []), finished with an error: Hit multiple errors:
Hit multiple errors:
exit status 1  prefix=[/<basePath>/bastion/compute] 
ERRO[0000] Encountered the following errors:
Hit multiple errors:
Hit multiple errors:
exit status 1
Cannot process module Module /<basePath>/bastion/compute (excluded: false, dependencies: [/<basePath>/bastion/storage]) because one of its dependencies, Module /<basePath>/bastion/storage (excluded: false, dependencies: []), finished with an error: Hit multiple errors:
Hit multiple errors:
exit status 1 

New output:

ERRO[0000] Module /<basePath>/bastion/storage has finished with an error: 1 error occurred:
	* exit status 1
  prefix=[/.../bastion/storage] 
ERRO[0000] Dependency /<basePath>/bastion/storage of module /<basePath>/bastion/compute just finished with an error. Module /<basePath>/bastion/compute will have to return an error too.  prefix=[/<basePath>/bastion/compute] 
ERRO[0000] Module /<basePath>/bastion/compute has finished with an error: Cannot process module Module /<basePath>/bastion/compute (excluded: false, dependencies: [/<basePath>/bastion/storage]) because one of its dependencies, Module /<basePath>/bastion/storage (excluded: false, dependencies: []), finished with an error: 1 error occurred:
	* exit status 1
  prefix=[/<basePath>/bastion/compute] 
ERRO[0000] 2 errors occurred:
	* Cannot process module Module /<basePath>/bastion/compute (excluded: false, dependencies: [/<basePath>/bastion/storage]) because one of its dependencies, Module /<basePath>/bastion/storage (excluded: false, dependencies: []), finished with an error: 1 error occurred:
	* exit status 1


	* exit status 1

[yorinasub17]

Thanks for your contribution! Changes LGTM! Let me kick off a regression build, and if it passes, we can merge this in.

[yorinasub17]

Looks like there is a build failure. Specifically, the check at https://github.com/gruntwork-io/terragrunt/blob/pull-request-1703/test/integration_test.go#L1502 and https://github.com/gruntwork-io/terragrunt/blob/pull-request-1703/test/integration_test.go#L1711 are failing with:

Object expected to be of type multierror.Error, but was *multierror.Error

[derom]

@yorinasub17 my bad, I thought it was a glitch during my local run :) Fixed

[yorinasub17]

Thanks for updating! Just kicked off a build.

[yorinasub17]

Build passed, so will go ahead and merge this in. Thanks again for your contribution!