Move docker to 16.04.
Move docker to 16.04.

jorgeomarmh/configuration,gsehub/configuration,EDUlib/configuration,hastexo/edx-configuration,proversity-org/configuration,appsembler/configuration,proversity-org/configuration,appsembler/configuration,hks-epod/configuration,hks-epod/configuration,Stanford-Online/configuration,stvstnfrd/configuration,jorgeomarmh/configuration,edx/configuration,michaelsteiner19/open-edx-configuration,Stanford-Online/configuration,michaelsteiner19/open-edx-configuration,armaan/edx-configuration,mitodl/configuration,rue89-tech/configuration,arbrandes/edx-configuration,jorgeomarmh/configuration,Stanford-Online/configuration,michaelsteiner19/open-edx-configuration,gsehub/configuration,open-craft/configuration,Stanford-Online/configuration,mitodl/configuration,hks-epod/configuration,hastexo/edx-configuration,stvstnfrd/configuration,arbrandes/edx-configuration,mitodl/configuration,rue89-tech/configuration,hastexo/edx-configuration,edx/configuration,Stanford-Online/configuration,mitodl/configuration,EDUlib/configuration,armaan/edx-configuration,edx/configuration,appsembler/configuration,jorgeomarmh/configuration,hastexo/edx-configuration,stvstnfrd/configuration,gsehub/configuration,proversity-org/configuration,armaan/edx-configuration,hks-epod/configuration,rue89-tech/configuration,arbrandes/edx-configuration,hks-epod/configuration,open-craft/configuration,open-craft/configuration,gsehub/configuration,proversity-org/configuration,appsembler/configuration,hastexo/edx-configuration,EDUlib/configuration,edx/configuration,stvstnfrd/configuration,EDUlib/configuration,rue89-tech/configuration,arbrandes/edx-configuration,rue89-tech/configuration,open-craft/configuration,proversity-org/configuration,armaan/edx-configuration,arbrandes/edx-configuration,EDUlib/configuration,michaelsteiner19/open-edx-configuration,gsehub/configuration,stvstnfrd/configuration