* add support for ECDSA keys
* Add support for HTTP signature
* use bytes.Buffer instead of strings.Builder
* Add unit tests, compliance with HTTP signature draft version 12
* Support (expires) parameter
* Validate list of signed headers does not have duplicate values
* move method to ProcessUtils
* Add http-signature security scheme
* add http_signature_test to security scheme
* remove http signature from petapi
* Add separate OAS file with support for HTTP signature
* Include HTTP signature in README file
* Add generated files for HTTP signature
* Add helper function to return public key, and add more unit tests for signature validation
* some people save their private key with file extensions other than .pem, so I am relaxing the validation of the private key suffix
* fix go compilation error for properties of type map and array
* fix go compilation error for properties of type date and datetime
* add missing shell script to bin/utils/ensure-up-to-date
* add missing shell script to bin/utils/ensure-up-to-date
* add missing shell script to bin/utils/ensure-up-to-date
* fix issue with 'date' type
* fix time import problem
* Add missing pom.xml files for golang
* Add missing unit test files for golang
* Add missing unit test files for golang. Must use class name prefix for enums
* Fix unit tests for go-experimental in OAS3
* Fix unit tests for go-experimental in OAS3
* Add code comments in codegen
* Fix compilation errors of generated go code
* Fix compilation errors of generated go code
* remove antihax from go-experimental, it is no longer used
* copy python testfile for ut purpose
* add error checkout in unit tests
* add unit tests
* add code comments
* move test foo.png file to correct location
* run samples scripts
* run samples scripts
