general improvements (#2)

* Replaced strutil.Md5 with crypto/md5 and encoding/hex to reduce dependency and potential allocations.

* Move to improved logging library.

* fixup! Move to improved logging library.

logging/logger_suite_test.go

@@ -0,0 +1,31 @@
+package libpack_logger
+
+import (
+	"testing"
+
+	assertions "github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/suite"
+)
+
+type LoggerTestSuite struct {
+	suite.Suite
+}
+
+var (
+	assert *assertions.Assertions
+)
+
+func (suite *LoggerTestSuite) BeforeTest(suiteName, testName string) {
+}
+
+func (suite *LoggerTestSuite) SetupTest() {
+	assert = assertions.New(suite.T())
+}
+
+// TearDownTest is run after each test to clean up
+func (suite *LoggerTestSuite) TearDownTest() {
+}
+
+func TestSuite(t *testing.T) {
+	suite.Run(t, new(LoggerTestSuite))
+}