[Travis] re-enable recursive submodules
[Travis] re-enable recursive submodules

jeeftor/jazzy,mbogh/jazzy,jeeftor/jazzy,Kapeli/jazzy,1ec5/jazzy,realm/jazzy,agentk/jazzy,emiscience/jazzy,PSPDFKit-labs/jazzy,1ec5/jazzy,PSPDFKit-labs/jazzy,pcantrell/jazzy,mbogh/jazzy,realm/jazzy,emiscience/jazzy,1ec5/jazzy,agentk/jazzy,agentk/jazzy,mbogh/jazzy,Kapeli/jazzy,emiscience/jazzy,pcantrell/jazzy,jeeftor/jazzy,Kapeli/jazzy,pcantrell/jazzy