Add allocation_mode to vm network config
Add allocation_mode: 'pool' to examples
Bump vcloud-core version dependency to 0.5.0
Update CHANGELOG for VM IP allocation by pool

Reflects changes in
https://github.com/alphagov/vcloud-launcher/pull/38/files.
Version 0.1.0

Bump version to 0.1.0 and update date in CHANGELOG.
Merge pull request #38 from alphagov/geriBatai-ip_pools

Support for VM IP pools