feat: Add --autoplan-file-list server flag.

[Omicron7]

This adds a new server flag that allows modifying the list of files that trigger default project planning.

We use terraform/atlantis to build AWS AMI's using packer and ansible. We wanted changes to the packer (*.pkr.hcl) and ansible (*.yml) files to trigger an autoplan when modified in a commit. It looked like we could do this with an atlantis.yml file (Workflow), but we have a large repo with 100's of small projects and rely on the default atlantis workflow. Defining atlantis.yml would require us to define every existing project, and all new projects in that workflow.

Instead, I added a server flag/ENV that would allow modifying/overriding the list of file patterns that trigger an autoplan.

--autoplan-file-list uses the same dockeringore syntax as Custom workflows autoplan when_modified. This allows for overriding the default list, adding more file types, and file exclusions.

Examples:

• Default: --autoplan-file-list="**/*.tf,**/*.tfvars,**/*.tfvars.json"
• Add packer and YML files: --autoplan-file-list="**/*.tf,**/*.tfvars,**/*.tfvars.json,**/*.pkr.hcl,**/*.yml"
• ENV var: ATLANTIS_AUTOPLAN_FILE_LIST="**/*.tf,**/*.hcl"

[codecov]

Codecov Report

Merging #1475 (da2f3c3) into master (921ebbc) will decrease coverage by 0.00%.
The diff coverage is 75.00%.

@@            Coverage Diff             @@
##           master    #1475      +/-   ##
==========================================
- Coverage   70.23%   70.23%   -0.01%     
==========================================
  Files          94       94              
  Lines        6441     6457      +16     
==========================================
+ Hits         4524     4535      +11     
- Misses       1533     1536       +3     
- Partials      384      386       +2     

Impacted Files	Coverage Δ
server/user_config.go	100.00% <ø> (ø)
server/events/project_command_builder.go	81.74% <50.00%> (-0.56%)	⬇️
server/events/project_finder.go	88.09% <70.00%> (-2.82%)	⬇️
cmd/server.go	79.55% <100.00%> (+0.46%)	⬆️
server/server.go	64.65% <100.00%> (+0.07%)	⬆️

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[nishkrishnan]

Nice work I'm in favor of the change just a couple questions/comments.

[Omicron7]

@nishkrishnan I've updated the PR to set the default value in cmd/server.go and added **/terragrunt.hcl to the list. This also adds pattern validation at startup which removes the need for error checking/catching in the project finder.

[Omicron7]

make test passes for me locally, not sure why circleci failed on the invalid pattern test.

[Omicron7]

@nishkrishnan I rebased this on latest master and fixed logging issue. Any help tracking down the failing test would be appreciated. make test succeeds locally for me. I'm not knowledgeable enough with go and circleci to figure out whats going on. I'm guessing a module version difference.