v0.6.0

Add security customizations to the bastion instance @syphernl (#34)

what

• Added the ability to encrypt the root block device, off by default.
• Added the ability to change the size of the root block device
• Added the ability to change the HTTP Metadata endpoint settings (e.g. disable it, force it to IMSv2)
• Example modified to encrypt the EBS + turn off IMSv2 per recommendations

why

• Checkov recommends to have the root block device encrypted and IMSv1 disabled. See references below for the rationale behind this recommendation.
  With the changes in this PR one can configure their Bastion to follow these recommendations.

references

• CKV_AWS_79: "Ensure Instance Metadata Service Version 1 is not enabled". Rationale behind this can be found in this AWS blog post.
• CKV_AWS_8: "Ensure all data stored in the Launch configuration EBS is securely encrypted" (https://docs.bridgecrew.io/docs/general_13)