Add a new pkg/crypto/keys, first cut

- provides three functions
     - GetRandomAlphaNumeric()
     - GetRandomAlphaNumericFull()
     - GetRandomBase64()
     - ValidAccessKey()

pkg/utils/crypto/keys/common.go

@@ -0,0 +1,10 @@
+package keys
+
+const (
+	MINIO_ACCESS_ID = 20
+	MINIO_SECRET_ID = 40
+)
+
+func isalnum(c byte) bool {
+	return '0' <= c && c <= '9' || 'A' <= c && c <= 'Z' || 'a' <= c && c <= 'z'
+}