修改kerberos相关 (#9)

1.修改域名为test.hadoop.com。
2.增加readme。

Reviewed-on: #9

kerberos/server/krb5.conf

@@ -4,11 +4,11 @@ kdc_tcp_ports = 88
 
 [realms]
 TEST.HADOOP.COM = {
-  master_key_type = aes256-cts
+  #master_key_type = aes256-cts
   acl_file = /etc/krb5kdc/kadm5.acl
   dict_file = /usr/share/dict/words
   admin_keytab = /var/krb5kdc/kadm5.keytab
   max_renewable_life = 7d 0h 0m 0s
-  supported_enctypes = aes256-cts-hmac-sha1-96:normal aes128-cts-hmac-sha1-96:normal des3-cbc-sha1:normal arcfour-hmac-md5:normal aes128-cts aes256-cts
+  supported_enctypes = aes256-cts:normal aes128-cts:normal des3-hmac-sha1:normal arcfour-hmac:normal des-hmac-sha1:normal des-cbc-md5:normal des-cbc-crc:normal
 }