Fix "bad file descriptor" error on travis ci (#7746)
Fix "bad file descriptor" error on travis ci (#7746)


dennisobrien/bokeh,jakirkham/bokeh,Karel-van-de-Plassche/bokeh,aavanian/bokeh,timsnyder/bokeh,Karel-van-de-Plassche/bokeh,jakirkham/bokeh,timsnyder/bokeh,timsnyder/bokeh,bokeh/bokeh,aavanian/bokeh,stonebig/bokeh,timsnyder/bokeh,ericmjl/bokeh,bokeh/bokeh,jakirkham/bokeh,ericmjl/bokeh,dennisobrien/bokeh,mindriot101/bokeh,Karel-van-de-Plassche/bokeh,stonebig/bokeh,bokeh/bokeh,mindriot101/bokeh,mindriot101/bokeh,stonebig/bokeh,bokeh/bokeh,dennisobrien/bokeh,Karel-van-de-Plassche/bokeh,jakirkham/bokeh,jakirkham/bokeh,ericmjl/bokeh,stonebig/bokeh,aavanian/bokeh,dennisobrien/bokeh,ericmjl/bokeh,mindriot101/bokeh,timsnyder/bokeh,dennisobrien/bokeh,bokeh/bokeh,aavanian/bokeh,Karel-van-de-Plassche/bokeh,aavanian/bokeh,ericmjl/bokeh