increase root vol size (#284)

## Description

Proposal to include a root volume definition in the Cloudformation
template to increase the root volume size(from the default 8Gb) of the
VMClarity Server to avoid very quickly running out of disk space when
performing scans. Proposed increase to 30 Gb which is the max free tier
limit.

## Type of Change

[ ] Bug Fix  
[ ] New Feature  
[ ] Breaking Change  
[ ] Refactor  
[ ] Documentation  
[ x] Other (please describe)  

Minor enhancement suggestion to avoid users rapidly running out of disk
space on the VM clarity Server when performing scans.

## Checklist

- [ x] I have read the [contributing guidelines](/CONTRIBUTING.md)
- [ x] Existing issues have been referenced (where applicable)
- [x ] I have verified this change is not present in other open pull
requests
- [n/a ] Functionality is documented
- [ x] All code style checks pass
- [ n/a] New code contribution is covered by automated tests
- [ n/a] All new and existing tests pass

This is a config change so some of the above are not applicable for cfn
changes.

installation/aws/VmClarity.cfn

@@ -76,6 +76,13 @@ Resources:
           - !Ref InstanceType
           - Arch
       KeyName: !Ref KeyName
+      BlockDeviceMappings:
+        - DeviceName: /dev/sda1
+          Ebs:
+            VolumeType: gp2
+            VolumeSize: '30'
+            DeleteOnTermination: 'true'
+            Encrypted: 'false'
       IamInstanceProfile:
         Ref: VmClarityServerInstanceProfile
       NetworkInterfaces: