Use shared configuration for credentials

This release simplifies use of AWS credentials. The tool will use credentials and configurations shared across ~/.aws/config and ~/.aws/credentials files.

Return URL only

v0.1.6

Merge branch 'master' of github.com:benderillo/s3url-presigner

Code cleanup

Removed unnecessary option and code.

Align with golang layout standards

This release aligns source code layout and project info with golang standards described here: https://github.com/golang-standards/project-layout

Initial release

Initial release of the tool

• Supports GET and PUT requests presigning