Format contrib repo to be more flat.

[n3wscott]

Fixes #508

Proposed Changes

• move github one level up.
• move awssqs one level up.

Release Note

NONE.

[n3wscott]

/assign @grantr

[knative-metrics-robot]

The following is the coverage report on pkg/.
Say /test pull-knative-eventing-contrib-go-coverage to re-run this coverage report

File	Old Coverage	New Coverage	Delta
awssqs/pkg/adapter/adapter.go	Do not exist	61.8%
awssqs/pkg/apis/sources/v1alpha1/aws_sqs_types.go	Do not exist	100.0%
awssqs/pkg/apis/sources/v1alpha1/register.go	Do not exist	100.0%
github/pkg/adapter/adapter.go	Do not exist	96.6%
github/pkg/apis/sources/v1alpha1/githubsource_types.go	Do not exist	86.7%
github/pkg/apis/sources/v1alpha1/register.go	Do not exist	100.0%
github/pkg/reconciler/githubsource.go	Do not exist	85.5%
github/pkg/reconciler/webhook_client.go	Do not exist	0.0%

[knative-prow-robot]

@n3wscott: The following test failed, say /retest to rerun them all:

Test name	Commit	Details	Rerun command
pull-knative-eventing-contrib-go-coverage	3a9e4bc	link	/test pull-knative-eventing-contrib-go-coverage

Full PR test history. Your PR dashboard.

Instructions for interacting with me using PR comments are available here. If you have questions or suggestions related to my behavior, please file an issue against the kubernetes/test-infra repository. I understand the commands that are listed here.

[grantr]

Coverage of github/pkg/reconciler/webhook_client.go was zero before; this PR doesn't change it.

[grantr]

/lgtm

I don't know of anything else that imports these packages, so I think they're safe to move.

[knative-prow-robot]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: grantr, n3wscott

The full list of commands accepted by this bot can be found here.

The pull request process is described here

Needs approval from an approver in each of these files:

• OWNERS [grantr,n3wscott]

Approvers can indicate their approval by writing /approve in a comment
Approvers can cancel approval by writing /approve cancel in a comment