command: Fix TestGraph_plan
command: Fix TestGraph_plan

The plan file writer requires a backend config to be present, but we don't
really need one for the sake of _this_ test, since we don't activate the
backend to render a plan graph, and so we just write in a placeholder.

gechr/terraform,pdecat/terraform,pdecat/terraform,apparentlymart/terraform,luis-silva/terraform,ewbankkit/terraform,rnaveiras/terraform,iljaskevic/terraform,heimweh/terraform,youhong316/terraform,tommynsong/terraform,pryorda/terraform,luis-silva/terraform,drebes/terraform,nlamirault/terraform,apparentlymart/terraform,brandontosch/terraform,VladRassokhin/terraform,ewbankkit/terraform,mattray/terraform,tommynsong/terraform,rnaveiras/terraform,gechr/terraform,youhong316/terraform,brandontosch/terraform,pryorda/terraform,VladRassokhin/terraform,mattray/terraform,pradeepbhadani/terraform,pdecat/terraform,mattray/terraform,VladRassokhin/terraform,pradeepbhadani/terraform,tpounds/terraform,drebes/terraform,youhong316/terraform,luis-silva/terraform,iljaskevic/terraform,heimweh/terraform,apparentlymart/terraform,luis-silva/terraform,VladRassokhin/terraform,rnaveiras/terraform,brandontosch/terraform,heimweh/terraform,tpounds/terraform,tpounds/terraform,youhong316/terraform,hashicorp/terraform,drebes/terraform,tommynsong/terraform,gechr/terraform,pryorda/terraform,brandontosch/terraform,apparentlymart/terraform,nlamirault/terraform,pradeepbhadani/terraform,pdecat/terraform,hashicorp/terraform,ewbankkit/terraform,hashicorp/terraform,mattray/terraform,drebes/terraform,tpounds/terraform,nlamirault/terraform,heimweh/terraform,iljaskevic/terraform,iljaskevic/terraform,ewbankkit/terraform,heimweh/terraform,brandontosch/terraform,apparentlymart/terraform