changed startup type to exec

examples/systemd/example-leds.service

+[Unit]
+Description=Example LEDs
+Requires=fadecandy.service
+
+[Service]
+Type=exec
+WorkingDirectory=/opt/fadecandy/examples/python
+ExecStart=/usr/bin/env python /opt/fadecandy/examples/python/chase.py
+Restart=always
+
+[Install]
+WantedBy=multi-user.target

examples/systemd/fadecandy.service

+[Unit]
+Description=Fadecandy Server
+After=network.target
+
+[Service]
+Type=exec
+WorkingDirectory=/opt/fadecandy/server
+ExecStart=/opt/fadecandy/server/fcserver config.json
+Restart=always
+
+[Install]
+WantedBy=multi-user.target