Seed OpenLDAP with bootstrap users including email addresses

Add docker/openldap/bootstrap.ldif which creates an ou=people OU and
three test users (admin, approver, staff) each with a mail attribute,
matching the database seeder. Mount the LDIF into the openldap container
and add --copy-service so it is loaded on first boot.

docker/openldap/bootstrap.ldif

@@ -0,0 +1,46 @@
+# People OU
+dn: ou=people,dc=travel,dc=local
+objectClass: organizationalUnit
+ou: people
+
+# Administrator
+dn: uid=admin,ou=people,dc=travel,dc=local
+objectClass: inetOrgPerson
+objectClass: posixAccount
+objectClass: shadowAccount
+cn: Administrator
+sn: Administrator
+uid: admin
+mail: admin@travel.local
+uidNumber: 1000
+gidNumber: 1000
+homeDirectory: /home/admin
+userPassword: password
+
+# Travel Approver
+dn: uid=approver,ou=people,dc=travel,dc=local
+objectClass: inetOrgPerson
+objectClass: posixAccount
+objectClass: shadowAccount
+cn: Travel Approver
+sn: Approver
+uid: approver
+mail: approver@travel.local
+uidNumber: 1001
+gidNumber: 1000
+homeDirectory: /home/approver
+userPassword: password
+
+# Staff Member
+dn: uid=staff,ou=people,dc=travel,dc=local
+objectClass: inetOrgPerson
+objectClass: posixAccount
+objectClass: shadowAccount
+cn: Staff Member
+sn: Member
+uid: staff
+mail: staff@travel.local
+uidNumber: 1002
+gidNumber: 1000
+homeDirectory: /home/staff
+userPassword: password