* 1. Add 'role-session-name' variable to action.yml
2. Configure roleSessionName with role-session-name from action or default value (GitHubActions)
* Add description on README.md
* update README.md
* update dist/index.js
* add test code
* update context based on comments
* Sanitize github actor tag
* Add some tests
* Sanitize Github actions workflow name
* Change sanitization character to an asterisk
* Update readme about assuming a role
* Tidy up assume role readme entry more
* Align sanitize spelling to use -ize
* typo: environement -> environment
* first draft attempt at adding role assumption option
* refinements
* const not var
* clean up asserts
* set explicit sts endpoint and clarify required inputs error message
* streamline mocks
* add new inputs to Action definition
* ignore .idea directory
* add initial assume role test
* make tests fail usefully when not in GitHub Actions
* add logic to handle suppression of stack trace
* pull credentials exports out into function
* convert environment variable patching to use object for source and add needed members
* add test for STS call
* compartmentalization and use custom user agent in role assumption STS client
* change DO_NOT_SUPRESS_STACK_TRACE to SHOW_STACK_TRACE
* update role-to-assume input description
