Added more tests

src/errors/Common.go

@@ -11,7 +11,6 @@ var (
 	InvalidNumber              = &Base{"Invalid number"}
 	InvalidExpression          = &Base{"Invalid expression"}
 	InvalidRune                = &Base{"Invalid rune"}
-	InvalidStatement           = &Base{"Invalid statement"}
 	MissingBlockStart          = &Base{"Missing '{'"}
 	MissingBlockEnd            = &Base{"Missing '}'"}
 	MissingExpression          = &Base{"Missing expression"}