Add rule ID to text output (#198)

Author: glb

output/formatter.go

@@ -45,7 +45,7 @@ const (
 
 var text = `Results:
 {{ range $index, $issue := .Issues }}
-[{{ $issue.File }}:{{ $issue.Line }}] - {{ $issue.What }} (Confidence: {{ $issue.Confidence}}, Severity: {{ $issue.Severity }})
+[{{ $issue.File }}:{{ $issue.Line }}] - {{ $issue.RuleID }}: {{ $issue.What }} (Confidence: {{ $issue.Confidence}}, Severity: {{ $issue.Severity }})
   > {{ $issue.Code }}
 
 {{ end }}