Update tests to use ALL command-line flags

[atc0005]

While working on #186, I encountered this test failure:

--- FAIL: TestValidate (0.00s)
    --- FAIL: TestValidate/LogLevel_set_to_valid_values (0.00s)
        validate_test.go:539: Config failed, but should have passed on valid value "emerg" for LogLevel: invalid option "emerg" provided for log level
        validate_test.go:536: Config passed as expected after setting LogLevel to "alert": <nil>
        validate_test.go:536: Config passed as expected after setting LogLevel to "critical": <nil>
        validate_test.go:536: Config passed as expected after setting LogLevel to "panic": <nil>
        validate_test.go:536: Config passed as expected after setting LogLevel to "fatal": <nil>
        validate_test.go:536: Config passed as expected after setting LogLevel to "error": <nil>
        validate_test.go:536: Config passed as expected after setting LogLevel to "warn": <nil>
        validate_test.go:536: Config passed as expected after setting LogLevel to "info": <nil>
        validate_test.go:536: Config passed as expected after setting LogLevel to "notice": <nil>
        validate_test.go:536: Config passed as expected after setting LogLevel to "debug": <nil>
        validate_test.go:536: Config passed as expected after setting LogLevel to "trace": <nil>
        validate_test.go:549: Validation successful after restoring LogLevel field

I had just replaced the "emergency" string here:

elbow/config/validate_test.go

Lines 519 to 531 in 788742b

	tests := []string{
	"emergency",
	"alert",
	"critical",
	"panic",
	"fatal",
	"error",
	"warn",
	"info",
	"notice",
	"debug",
	"trace",
	}

with the new constant:

                tests := []string{
-                       "emergency",
+                       logging.LogLevelEmerg,

which is defined as:

	// unusable; a panic condition. This level is mapped to logrus.PanicLevel
	// and syslog.LOG_EMERG. logrus calls panic.
	LogLevelEmerg string = "emerg"

I pulled that from here:

elbow/logging/logging_unix.go

Lines 46 to 51 in 788742b

	switch logLevel {
	// TODO: Evaluate replacing bare strings with constants (see constants.go)
	case "emerg", "panic":
	// syslog: System is unusable; a panic condition.
	// logrus: calls panic
	syslogLogLevel = syslog.LOG_EMERG

which is being "tested" like so:

elbow/logging/logging_test.go

Lines 127 to 139 in 788742b

	tests := []test{
	test{logLevel: "emerg", loggerLevel: logrus.PanicLevel},
	test{logLevel: "panic", loggerLevel: logrus.PanicLevel},
	test{logLevel: "alert", loggerLevel: logrus.FatalLevel},
	test{logLevel: "critical", loggerLevel: logrus.FatalLevel},
	test{logLevel: "fatal", loggerLevel: logrus.FatalLevel},
	test{logLevel: "error", loggerLevel: logrus.ErrorLevel},
	test{logLevel: "warn", loggerLevel: logrus.WarnLevel},
	test{logLevel: "notice", loggerLevel: logrus.WarnLevel},
	test{logLevel: "info", loggerLevel: logrus.InfoLevel},
	test{logLevel: "debug", loggerLevel: logrus.DebugLevel},
	test{logLevel: "trace", loggerLevel: logrus.TraceLevel},
	}

The expected log level value is being checked like so:

elbow/config/validate.go

Line 128 in 788742b

case *c.LogLevel == "emergency":

which apparently only checks against the command-line flag value, not what is keyed off of to do the final syslog and logrus calls.

[atc0005]

I checked the README to be sure, and found that the emergency option for ``--log-level` is what we have documented as the valid command-line flag option:

https://github.com/atc0005/elbow/blame/788742bc682e57958d30113e52355efffc8d7b32/README.md#L202

I vaguely recall writing the Validate() function based on that literal value.