Add exercises/image-share

Change-Id: Ib8ab42b829b568897308f43c95173e7d224e3863
Merge branch 'install-pip' into dt-test
Merge branch 'nova-plugin' into dt-test
Merge branch 'docker' into dt-test
Merge branch 'image-member-exercise' into dt-test
Merge branch 'screen-stop' into dt-test
Merge branch 'doc-shocco-cleanup' into dt-test
Merge branch 'update-usb-tools' into dt-test