Bug 12455: adding unit tests for the module C4/SMS.pm

Bug 12455: adding unit tests for the module C4/SMS.pm

The module C4/SMS.pm was not tested

Test plan:
1/ Execute the command : prove t/SMS.t
2/ The result has to be a success without error or warning :
t/SMS.t .. ok
All tests successful.
Files=1, Tests=7,  1 wallclock secs ( 0.03 usr  0.01 sys +  0.17 cusr  0.02 csys =  0.23 CPU)
Result: PASS

Signed-off-by: Bernardo Gonzalez Kriegel <bgkriegel@gmail.com>
Replace stub test, all test pass.
Removed "use strict/warnings", no need for that with "use Modern::Perl"
No koha-qa errors

Signed-off-by: Katrin Fischer <Katrin.Fischer.83@web.de>
Signed-off-by: Tomas Cohen Arazi <tomascohen@gmail.com>