adding systemd script to manage otsd

Author: RCasatta

contrib/systemd/bitcoind-ready.sh

@@ -0,0 +1,5 @@
+#/bin/bash
+until /usr/local/bin/bitcoin-cli getblockchaininfo
+do
+  /bin/sleep 3
+done

contrib/systemd/otsd.service

@@ -0,0 +1,15 @@
+[Unit]
+Description=OpenTimestamps server
+After=bitcoind.service
+
+[Service]
+User=ots
+Group=ots
+ExecStartPre=/bin/bash /usr/local/bin/bitcoind-ready.sh
+ExecStart=/home/ots/opentimestamps-server/otsd -v
+Restart=on-failure
+
+KillSignal=SIGINT
+
+[Install]
+WantedBy=multi-user.target