Build issues when using python 3

WARNING: dot code 'blockdiag {\n   OPNsense [shape="cisco.firewall", label=""];\n   internet [shape="cloud"];\n   private_net [shape="cloud", label="private net"];\n   Gateway1 [shape="cisco.router", label=""];\n   Gateway2 [shape="cisco.router", label=""];\n   Gateway3 [shape="cisco.router", label=""];\n   OPNsense -> Gateway1 -> internet;\n   OPNsense -> Gateway2 -> internet [style = dotted];\n   OPNsense -> Gateway3 -> private_net;\n\n}': integer argument expected, got float
WARNING: dot code 'nwdiag {\n\n    span_width = 90;\n    node_width = 180;\n    Internet [shape = "cisco.cloud"];\n    fileserver [label="File Server",shape="cisco.fileserver",address="192.168.1.10"];\n    fileserver -- switchlan;\n\n    network LAN {\n      switchlan [label="",shape = "cisco.workgroup_switch"];\n      label = " LAN";\n      address ="192.168.1.1.x/24";\n      fw1 [address="192.168.1.1/24"];\n    }\n\n    network WAN  {\n      label = " WAN";\n      fw1 [shape = "cisco.firewall", address="172.18.0.164"];\n      Internet;\n    }\n\n    network Remote {\n        Internet;\n        laptop [address="172.10.10.55 (WANIP),10.10.0.1 (IPsec)",label="Remote User",shape="cisco.laptop"];\n    }\n  }': integer argument expected, got float

https://github.com/blockdiag/blockdiag/pull/111
https://github.com/blockdiag/blockdiag/pull/130