Error with installing postgresql-9.5-postgis-2.2 on Debian 8.5 jessie

Question

I have PostgreSQL 9.5 installed and working on Debian 8.5 jessie.

The following packages have unmet dependencies: 
  postgresql-9.5-postgis-2.2 : Depends: libgdal1h (>= 1.9.0) but it is not going to be installed
                               Depends: liblwgeom-2.2-5 (>= 2.2.0) but it is not going to be installed
                               Depends: libsfcgal1 (>= 1.2.0) but it is not going to be installed 
  E: Unable to correct problems, you have held broken packages.

tried already fixing:

root@dbServer:~$ apt-get -f install
 Reading package lists... Done
 Building dependency tree
 Reading state information... Done
 0 upgraded, 0 newly installed, 0 to remove and 0 not upgraded.

My sources.list:

deb http://ftp.debian.org/debian jessie main contrib non-free
deb http://ftp.debian.org/debian jessie-updates main contrib non-free
deb http://security.debian.org jessie/updates main contrib non-free
deb http://ftp.de.debian.org/debian jessie main
deb http://ftp.debian.org/debian stretch main contrib non-free
deb-src http://ftp.debian.org/debian stretch main contrib non-free
deb http://apt.postgresql.org/pub/repos/apt jessie-pgdg main

Does anyone have an idea what should I do to move further? Thank You

Answer 1

Ok. If anyone more had the problem - i removed testing.pref from /etc/apt/preferences.d/ and removed

deb http://ftp.debian.org/debian stretch main contrib non-free
deb-src http://ftp.debian.org/debian stretch main contrib non-free\

from sources.list so all dependencies were downgraded to stable jessie version