Awscurl

Change long:
* add support for MacOS brew package manager
* relax urllib3 version requirements

Changes:
* fix up url parsing (affects websocket connections url)
* Split up signature generation steps and add tests to allow for core code re-use in other projects
* Create LICENSE file and indicate MIT usage
* Fixup Dockerfile
* Add support non-English text data in printout of headers and response body
* Add python 3.8 as supported/tested python version

Experimental support for aws instance credentials

Resolve install issue

Changelog since v0.12 (attribution where possible)

Adding the option (-k) to ignore SSL verification errors (iulianmac)
data_binary parameter in main() function (mariosotil)
Removing is_text function and using a flag to send the payload as binary
Merge pull request 37 from okigan/feature/issues/34
fixes 39 need to obfuscate AWS credentials used for testing
Merge pull request 38 from okigan/issue/33
fixes 33 URI encoding
Basic Docker container (bradleyjames)
add publish script