package.rpm state does not default to present

[ryane]

example:

package.rpm "mc" {
  name = "mc"
}

$ /usr/local/bin/converge plan --local rpm.hcl
2016-10-28T15:00:56Z |INFO| serving     addr=:47740 component=rpc
2016-10-28T15:00:56Z |WARN| skipping module verification        component=client
2016-10-28T15:00:56Z |INFO| got status  component=client file=rpm.hcl id=root/package.rpm.mc run=STARTED stage=PLAN
2016-10-28T15:00:57Z |INFO| got status  component=client file=rpm.hcl id=root run=STARTED stage=PLAN

root/package.rpm.mc:
 Messages:
 Has Changes: yes
 Changes:
  mc: "absent" => ""

Summary: 0 errors, 1 changes

$ /usr/local/bin/converge apply --local rpm.hcl
2016-10-28T15:01:03Z |INFO| serving     addr=:47740 component=rpc
2016-10-28T15:01:03Z |WARN| skipping module verification        component=client
2016-10-28T15:01:03Z |INFO| got status  component=client file=rpm.hcl id=root/package.rpm.mc run=STARTED stage=APPLY
2016-10-28T15:01:04Z |INFO| got status  component=client file=rpm.hcl id=root run=STARTED stage=APPLY

root/package.rpm.mc:
 Error: root/package.rpm.mc still has changes after apply: exit status 1
 Messages:
 Has Changes: yes
 Changes:
  mc: "absent" => ""

Summary: 2 errors, 1 changes

 * root/package.rpm.mc: root/package.rpm.mc still has changes after apply: exit status 1
 * root: error in dependency "root/package.rpm.mc"

The preparer uses a default struct tag but it looks like that tag is not actually implemented. We should either explicitly require State to be specified or default it to "present".

If we do the latter, should we implement a default struct tag?

[stevendborrelli]

Feels like having a default struct tag would make things easier for module writers.

[rebeccaskinner]

fixed in #463