* Add golangci-lint as linting tool
* Disable failing staticchecks to start; GitHub issue to handle coming soon
* Run `goimports -w` to repair all source files that have improperly
formatted imports
* makefile: Add ci-lint target to run on travis
This change adds a new make target for running golangci-lint on newly
added Go files only. This target is expected to run during Packer ci builds.
* .github/contributing: Add code linting instructions
* travis: Update job configuration to run parallel builds
to accept a list of strings (for Amazon builders).
Per this change, `temporary_security_group_source_cidr` in the configuration:
1. Will be renamed to `temporary_security_group_source_cidrs`.
2. Will accept a list of CIDRs.
3. Will have its documentation updated to reflect this change.
4. Will have a fixer attached for newer templates to avail of.
Megan Marsh
Wilken Rivera
Akshat Mahajan