Added forced LuaSocket tests to travis builds.
Added forced LuaSocket tests to travis builds.

kernelsauce/turbo,zcsteele/turbo,YuanPeir-Chen/turbo-support-mipsel,luastoned/turbo,YuanPeir-Chen/turbo-support-mipsel,ddysher/turbo,mniestroj/turbo,ddysher/turbo,zcsteele/turbo,luastoned/turbo