Fix delete failed because association creation failed

Modify if the eip association is not created successful,
don't try to delete it.

Implements blueprint implement-ec2eip-updatable

Change-Id: Ifa883c31214c4cc367751766efcb6b775d1b4ffe
Refactor functions in eip.py

Refactor functions in eip.py for some similar codes.

Implements blueprint implement-ec2eip-updatable

Change-Id: I44d49fd1cc126b5cc318b9ccbe317623f6170ccf
Implement BlockDeviceMappings for LaunchConfiguration

We should support the BlockDeviceMappings for
AWS::AutoScaling::LaunchConfiguration resource to be
compatible with AWSCloudFormation, thus we can take
BlockDeviceMappings for instances in AutoScalingGroup
and InstanceGroup.

Implements blueprint implement-launchconfiguration-bdm

Change-Id: I26b13b8e98190fa4bb4223b5eed9970648d7ee35
Merge "Fix delete failed because association creation failed"
Merge "Refactor functions in eip.py"
Merge "Implement BlockDeviceMappings for LaunchConfiguration"