map keys cannot include special characters

[wendorf]

If I specify:

vars:
  domains:
    "*.example.com": my-favorite-domain

I generate the args: -var 'domains={*.example.com="my-favorite-domain"}' and Terraform throws the error:

invalid value "domains={*.example.com=\"my-favorite-domain\"}" for flag -var: Cannot parse value for variable ("{*.example.com=\"my-favorite-domain\"}") as valid HCL: At 1:6: illegal char

To resolve this, I must escape the key myself:

vars:
  domains:
    "\"*.example.com\"": my-favorite-domain

to generate the args: -var 'domains={"*.example.com"="my-favorite-domain"}'

[ljfranklin]

Rolling this issue into #57