qi.tests: Makes path concatenation portable in `Application` tests.
qi.tests: Makes path concatenation portable in `Application` tests.

Path were concatenated as strings, explicitly specifying the path separator
('/'). This is not portable as separator differs according to OS. `qi::Path`
already abstracts this out and is now used instead of string concatenation.

Change-Id: I08d5c1e1e4f4919e6d7cf9fb167c4e7e38e0c49a
Reviewed-on: http://gerrit2.aldebaran.lan/1186
Reviewed-by: jmonnon <8898eaf233516e520f996a244ca8a12d20f948b1@aldebaran.com>
Reviewed-by: gerrit <3b97070d46ccd66422a8e7b83e6967ed84780538@aldebaran-robotics.com>
Tested-by: gerrit <3b97070d46ccd66422a8e7b83e6967ed84780538@aldebaran-robotics.com>
Reviewed-by: philippe.martin <a3db8b74c3cf86a5cf091dca4e2125b498be933d@softbankrobotics.com>
Reviewed-by: vincent.palancher <f8ff75e1c61314c499fafa8de0d9e004e87e66b0@softbankrobotics.com>

aldebaran/libqi,aldebaran/libqi,aldebaran/libqi