fix: recognize license

[hoffa]

Issue #, if available

Description of changes

Before:

After (see https://github.com/hoffa/serverless-application-model):

Description of how you validated changes

The {} come from the original commit, where the date/name placeholders were delimited with them:

serverless-application-model/LICENSE

Line 189 in 38b4a78

Copyright {yyyy} {name of copyright owner}

However the original Apache-2.0 license (at the time of checking) uses square brackets: https://www.apache.org/licenses/LICENSE-2.0.txt

Checklist

• Adheres to the development guidelines
• Add/update transform tests
  • Using correct values
  • Using wrong values
• Add/update integration tests

Examples?

Please reach out in the comments if you want to add an example. Examples will be
added to sam init through aws/aws-sam-cli-app-templates.

By submitting this pull request, I confirm that my contribution is made under the terms of the Apache 2.0 license.