Make build friendly to in-source builds.

v0.3.6

Enabled in-source build. (#52)

v0.3.5

sts http stream leak fix

Client bootstrap API changes

Adapt to API changes in aws-c-io v0.4.20

Body signing is now an enum to enable differences between unsigned payloads between services.

S3's sign body is a little different. (#46)

* S3's sign body is a little different.

* Changed sign body flag to an enum.

Add better credentials provider error handling

v0.3.2

Add handling for NULL credentials (#44)

STS Credentials Provider

Sts creds provider (#40)

STS credentials provider, honor role_arn in the credentials and config files, private xml parser implementation.

v0.3.0

Shutdown callbacks, simplifications

Async Signing Error Handling

Errors that are raised during the signing process are now passed through to the on_complete callback.

Asynchronous Signer

The signing API is now async, to better support the required stage of credentials fetching.

Fixes to sigv4 signer query string, properly sign session tokens

When doing query signing, move the security token to the query string…

…… (#34)

* When doing query signing, move the security token to the query string instead of a header.