oeqa/selftest: Added new testsuite for image features.

oeqa/selftest: Added new testsuite for image features.

 Automated 5 oe-selftest testcase:
    - 1107: Check if non root user can connect via ssh without password
    - 1115: Check if all users can connect via ssh without password
    - 1114: Check rpm version 4 support on image
    - 1101: Check if efi/gummiboot images can be buit
    - 1103: Check that wic command can create efi/gummiboot installation images

Signed-off-by: Daniel Istrate <daniel.alexandrux.istrate@intel.com>
Signed-off-by: Ross Burton <ross.burton@intel.com>