Always panic on internal failures

These uses of `feedback.Error()` in the event of internal failures was a departure from the convention established in
the rest of the code of using `feedback.Error()` only for failures resulting from external issues, and panic() for those
resulting from internal issues (in which case the traceback is useful).

Author: per1234

check/check.go

@@ -18,7 +18,6 @@ package check
 
 import (
 	"fmt"
-	"os"
 
 	"github.com/arduino/arduino-check/check/checkconfigurations"
 	"github.com/arduino/arduino-check/check/checkdata"
@@ -40,8 +39,7 @@ func RunChecks(project project.Type) {
 	for _, checkConfiguration := range checkconfigurations.Configurations() {
 		runCheck, err := shouldRun(checkConfiguration, project)
 		if err != nil {
-			feedback.Errorf("Error while determining whether to run check: %v", err)
-			os.Exit(1)
+			panic(err)
 		}
 
 		if !runCheck {

result/result.go

@@ -21,15 +21,13 @@ import (
 	"encoding/json"
 	"fmt"
 	"html/template"
-	"os"
 
 	"github.com/arduino/arduino-check/check/checkconfigurations"
 	"github.com/arduino/arduino-check/check/checklevel"
 	"github.com/arduino/arduino-check/check/checkresult"
 	"github.com/arduino/arduino-check/configuration"
 	"github.com/arduino/arduino-check/configuration/checkmode"
 	"github.com/arduino/arduino-check/project"
-	"github.com/arduino/arduino-check/result/feedback"
 	"github.com/arduino/go-paths-helper"
 )
 
@@ -95,8 +93,7 @@ func (results *Type) Initialize() {
 func (results *Type) Record(checkedProject project.Type, checkConfiguration checkconfigurations.Type, checkResult checkresult.Type, checkOutput string) string {
 	checkLevel, err := checklevel.CheckLevel(checkConfiguration, checkResult)
 	if err != nil {
-		feedback.Errorf("Error while determining check level: %v", err)
-		os.Exit(1)
+		panic(fmt.Errorf("Error while determining check level: %v", err))
 	}
 
 	summaryText := fmt.Sprintf("Check %s result: %s", checkConfiguration.ID, checkResult)