During interactive session of `ipa-adtrust-install` the user needs to
answer several questions. This was done by sending all answers to
the processes stdin without analyzing the questions.
If the installation scenario changes at some point we can get on of the
following results:
* the test fails in the end and the root cause is not obvious
* if a new question was added
* test does not fail but answers are provided for wrong questions -
in this case scope of test case changes without being noticed
If we use `pexpect` for controlling the session, the test will fail
immediately when it encounters unexpected question.
Reviewed-By: Alexander Bokovoy <abokovoy@redhat.com>
caeed7e2d1