tests/krb5/as_req_tests.py: add simple test_as_req_enc_timestamp test

tests/krb5/as_req_tests.py: add simple test_as_req_enc_timestamp test

Example commands:

Windows 2012R2:
SERVER=172.31.9.188 SMB_CONF_PATH=/dev/null STRICT_CHECKING=1 DOMAIN=W2012R2-L6 REALM=W2012R2-L6.BASE CLIENT_USERNAME=ldaptestuser CLIENT_PASSWORD=a1B2c3D4 CLIENT_AS_SUPPORTED_ENCTYPES=28 KRBTGT_KVNO=2 KRBTGT_AES256_KEY_HEX=2eb6d146a2653d333cdbfb641a4efbc3de81af49e878e112bb4f6cbdd73fca52 KRBTGT_RC4_KEY_HEX=4e6d99c30e5fab901ea71f8894289d3b python/samba/tests/krb5/as_req_tests.py AsReqKerberosTests
SERVER=172.31.9.188 SMB_CONF_PATH=/dev/null STRICT_CHECKING=1 DOMAIN=W2012R2-L6 REALM=W2012R2-L6.BASE CLIENT_USERNAME=administrator CLIENT_PASSWORD=A1b2C3d4 CLIENT_AS_SUPPORTED_ENCTYPES=4 KRBTGT_KVNO=2 KRBTGT_AES256_KEY_HEX=2eb6d146a2653d333cdbfb641a4efbc3de81af49e878e112bb4f6cbdd73fca52 KRBTGT_RC4_KEY_HEX=4e6d99c30e5fab901ea71f8894289d3b python/samba/tests/krb5/as_req_tests.py AsReqKerberosTests
SERVER=172.31.9.188 SMB_CONF_PATH=/dev/null STRICT_CHECKING=1 DOMAIN=W2012R2-L6 REALM=W2012R2-L6.BASE ADMIN_USERNAME=administrator ADMIN_PASSWORD=A1b2C3d4 python/samba/tests/krb5/as_req_tests.py
SERVER=172.31.9.188 SMB_CONF_PATH=/dev/null STRICT_CHECKING=1 DOMAIN=W2012R2-L6 REALM=W2012R2-L6.BASE ADMIN_USERNAME=administrator ADMIN_PASSWORD=A1b2C3d4 CLIENT_USERNAME=administrator CLIENT_PASSWORD=A1b2C3d4 CLIENT_AS_SUPPORTED_ENCTYPES=4 CLIENT_KVNO=1 python/samba/tests/krb5/as_req_tests.py
SERVER=172.31.9.188 SMB_CONF_PATH=/dev/null STRICT_CHECKING=1 DOMAIN=W2012R2-L6 REALM=W2012R2-L6.BASE ADMIN_USERNAME=administrator ADMIN_PASSWORD=A1b2C3d4 CLIENT_USERNAME=ldaptestuser CLIENT_PASSWORD=a1B2c3D4 CLIENT_AS_SUPPORTED_ENCTYPES=28 CLIENT_KVNO=4 python/samba/tests/krb5/as_req_tests.py

Windows 2008R2:
SERVER=172.31.9.133 SMB_CONF_PATH=/dev/null STRICT_CHECKING=1 DOMAIN=W4EDOM-L4 REALM=W4EDOM-L4.BASE CLIENT_USERNAME=cifsmount CLIENT_PASSWORD=A1b2C3d4-08 CLIENT_AS_SUPPORTED_ENCTYPES=28 CLIENT_KVNO=17 KRBTGT_KVNO=2 KRBTGT_AES256_KEY_HEX=550aea2ea2719cb81c87692569796d1b3a099d433a93438f53bee798cc2f83be KRBTGT_RC4_KEY_HEX=dbc0d1feaaca3d5abc6794857b7f6fe0 python/samba/tests/krb5/as_req_tests.py
SERVER=172.31.9.133 SMB_CONF_PATH=/dev/null STRICT_CHECKING=1 DOMAIN=W4EDOM-L4 REALM=W4EDOM-L4.BASE CLIENT_USERNAME=administrator CLIENT_PASSWORD=A1b2C3d4 CLIENT_AS_SUPPORTED_ENCTYPES=4 CLIENT_KVNO=1 KRBTGT_KVNO=2 KRBTGT_AES256_KEY_HEX=550aea2ea2719cb81c87692569796d1b3a099d433a93438f53bee798cc2f83be KRBTGT_RC4_KEY_HEX=dbc0d1feaaca3d5abc6794857b7f6fe0 python/samba/tests/krb5/as_req_tests.py
SERVER=172.31.9.133 SMB_CONF_PATH=/dev/null STRICT_CHECKING=1 DOMAIN=W4EDOM-L4 REALM=W4EDOM-L4.BASE ADMIN_USERNAME=administrator ADMIN_PASSWORD=A1b2C3d4 CLIENT_USERNAME=administrator CLIENT_PASSWORD=A1b2C3d4 CLIENT_AS_SUPPORTED_ENCTYPES=4 CLIENT_KVNO=1 python/samba/tests/krb5/as_req_tests.py
SERVER=172.31.9.133 SMB_CONF_PATH=/dev/null STRICT_CHECKING=1 DOMAIN=W4EDOM-L4 REALM=W4EDOM-L4.BASE ADMIN_USERNAME=administrator ADMIN_PASSWORD=A1b2C3d4 CLIENT_USERNAME=cifsmount CLIENT_PASSWORD=A1b2C3d4-08 CLIENT_AS_SUPPORTED_ENCTYPES=28 CLIENT_KVNO=17 python/samba/tests/krb5/as_req_tests.py
SERVER=172.31.9.133 SMB_CONF_PATH=/dev/null STRICT_CHECKING=1 DOMAIN=W4EDOM-L4 REALM=W4EDOM-L4.BASE ADMIN_USERNAME=administrator ADMIN_PASSWORD=A1b2C3d4 python/samba/tests/krb5/as_req_tests.py

Samba:
SERVER=172.31.9.163 SMB_CONF_PATH=/dev/null STRICT_CHECKING=0 DOMAIN=W4EDOM-L4 REALM=W4EDOM-L4.BASE CLIENT_USERNAME=cifsmount CLIENT_PASSWORD=A1b2C3d4-08 CLIENT_AS_SUPPORTED_ENCTYPES=28 CLIENT_KVNO=17 KRBTGT_KVNO=2 KRBTGT_AES256_KEY_HEX=550aea2ea2719cb81c87692569796d1b3a099d433a93438f53bee798cc2f83be KRBTGT_RC4_KEY_HEX=dbc0d1feaaca3d5abc6794857b7f6fe0 python/samba/tests/krb5/as_req_tests.py
SERVER=172.31.9.163 SMB_CONF_PATH=/dev/null STRICT_CHECKING=0 DOMAIN=W4EDOM-L4 REALM=W4EDOM-L4.BASE CLIENT_USERNAME=administrator CLIENT_PASSWORD=A1b2C3d4 CLIENT_AS_SUPPORTED_ENCTYPES=4 CLIENT_KVNO=1 KRBTGT_KVNO=2 KRBTGT_AES256_KEY_HEX=550aea2ea2719cb81c87692569796d1b3a099d433a93438f53bee798cc2f83be KRBTGT_RC4_KEY_HEX=dbc0d1feaaca3d5abc6794857b7f6fe0 python/samba/tests/krb5/as_req_tests.py
SERVER=172.31.9.163 SMB_CONF_PATH=/dev/null STRICT_CHECKING=0 DOMAIN=W4EDOM-L4 REALM=W4EDOM-L4.BASE ADMIN_USERNAME=administrator ADMIN_PASSWORD=A1b2C3d4 CLIENT_USERNAME=administrator CLIENT_PASSWORD=A1b2C3d4 CLIENT_AS_SUPPORTED_ENCTYPES=4 CLIENT_KVNO=1 python/samba/tests/krb5/as_req_tests.py
SERVER=172.31.9.163 SMB_CONF_PATH=/dev/null STRICT_CHECKING=0 DOMAIN=W4EDOM-L4 REALM=W4EDOM-L4.BASE ADMIN_USERNAME=administrator ADMIN_PASSWORD=A1b2C3d4 CLIENT_USERNAME=cifsmount CLIENT_PASSWORD=A1b2C3d4-08 CLIENT_AS_SUPPORTED_ENCTYPES=28 CLIENT_KVNO=17 python/samba/tests/krb5/as_req_tests.py
SERVER=172.31.9.163 SMB_CONF_PATH=/dev/null STRICT_CHECKING=0 DOMAIN=W4EDOM-L4 REALM=W4EDOM-L4.BASE ADMIN_USERNAME=administrator ADMIN_PASSWORD=A1b2C3d4 python/samba/tests/krb5/as_req_tests.py

Signed-off-by: Stefan Metzmacher <metze@samba.org>
Reviewed-by: Andrew Bartlett <abartlet@samba.org>