add support for geth_extra_flags list

Signed-off-by: Jakub Sokołowski <jakub@status.im>

defaults/main.yml

@@ -61,6 +61,8 @@ geth_v5disc_enabled: true
 # List of trusted peers to connect to
 geth_trusted_peers: []
 geth_trusted_peers_file: '{{ geth_cont_vol }}/data/trusted-nodes.json'
+# Any additional flags you want to provide
+geth_extra_flags: []
 
 # Custom bootnodes
 geth_bootnodes: []

templates/docker-compose.yml.j2

@@ -82,3 +82,6 @@ services:
       --datadir=/data
       --password=/keys/account.pass
       --keystore=/keys
+{% for extra_flag in geth_extra_flags %}
+      {{ extra_flag }}
+{% endfor %}