Trouble installing postgresql server on Amazon Linux

Hello,

I'm trying to install postgresql on an Amazon Linux AMI release 2015.09. I
got the rpm for Amazon Linux AMI 2015.03 - x86_64 under PostgreSQL 9.3
linked here:
http://yum.postgresql.org/repopackages.php

But a yum install complains that it requires systemd-units, which I
haven't figure out how to get. The yum command and result:

]# yum -y install postgresql93 postgresql93-server postgresql93-contrib
postgresql93-libs
Loaded plugins: priorities, update-motd, upgrade-helper
Repository pgdg93 is listed more than once in the configuration
Repository pgdg93-source is listed more than once in the configuration
8 packages excluded due to repository priority protections
Resolving Dependencies
--> Running transaction check
---> Package postgresql93.x86_64 0:9.3.10-1PGDG.rhel7 will be installed
---> Package postgresql93-contrib.x86_64 0:9.3.10-1PGDG.rhel7 will be
installed
---> Package postgresql93-libs.x86_64 0:9.3.10-1PGDG.rhel7 will be installed
---> Package postgresql93-server.x86_64 0:9.3.10-1PGDG.rhel7 will be
installed
--> Processing Dependency: systemd-units for package:
postgresql93-server-9.3.10-1PGDG.rhel7.x86_64
--> Processing Dependency: systemd-units for package:
postgresql93-server-9.3.10-1PGDG.rhel7.x86_64
--> Finished Dependency Resolution
Error: Package: postgresql93-server-9.3.10-1PGDG.rhel7.x86_64 (pgdg93)
Requires: systemd-units
You could try using --skip-broken to work around the problem
You could try running: rpm -Va --nofiles --nodigest

----------------------------------------------------------------------------------------

The --skip-broken option returns Errno 256
# yum -y install --skip-broken postgresql93 postgresql93-server
postgresql93-contrib postgresql93-libs
.
.
.
Error downloading packages:
postgresql93-contrib-9.3.10-1PGDG.rhel7.x86_64: failure:
postgresql93-contrib-9.3.10-1PGDG.rhel7.x86_64.rpm from pgdg93: [Errno 256]
No more mirrors to try.
postgresql93-9.3.10-1PGDG.rhel7.x86_64: failure:
postgresql93-9.3.10-1PGDG.rhel7.x86_64.rpm from pgdg93: [Errno 256] No more
mirrors to try.
postgresql93-libs-9.3.10-1PGDG.rhel7.x86_64: failure:
postgresql93-libs-9.3.10-1PGDG.rhel7.x86_64.rpm from pgdg93: [Errno 256] No
more mirrors to try.

----------------------------------------------------------------------------------------

I've tried quite a few other things, but now I'm back to the same error.
Do you have any suggestions?

Thank you,
Augori