Travis jobs hang, waiting to be queued

Only the first build starts, the others wait forever waiting to be queued:

link:
https://travis-ci.org/jpmorganchase/perspective/builds/486544059

Here is my .yaml

sudo: required
language: node_js
node_js: "8"

services:
  - docker

matrix:
  include:
    - env: TEST=WASM
      os: linux
      dist: trusty

    - language: 
        - c++
        - node_js
      env: TEST=CPP
      os: linux
      dist: trusty

    - python: "3.6"
      language: 
        - python
        - node_js
      env: TEST=PYTHON
      cache: pip
      os: linux
      dist: trusty

    - language: 
        - c++
        - node_js
      env: TEST=CPP_UBU14
      os: linux
      dist: trusty
      compiler: gcc

    - language: 
        - c++
        - node_js
      env: TEST=CPP_UBU14
      os: linux
      dist: trusty
      compiler: clang

    - language: 
        - c++
        - node_js
      env: TEST=CPP_UBU16
      os: linux
      dist: xenial
      compiler: gcc

    - language: 
        - c++
        - node_js
      env: TEST=CPP_UBU16
      os: linux
      dist: xenial
      compiler: clang

    - language: 
        - c++
        - node_js
      env: TEST=CPP_OSX
      os: osx
      compiler: clang

cache:
  yarn: true
  directories:
    - node_modules
    - packages/perspective/node_modules
    - packages/perspective-examples/node_modules
    - packages/perspective-jupyterlab/node_modules
    - packages/perspective-viewer/node_modules
    - packages/perspective-viewer-highcharts/node_modules
    - packages/perspective-viewer-hypergrid/node_modules

env:
  global:
    - EM_USE_GLOBAL_CACHE=1


install:
  - yarn

script:
  - if [ "$TEST" = "WASM" ]; then yarn lint; fi
  - if [ "$TEST" = "WASM" ]; then PSP_DOCKER=1 yarn build; fi
  - if [ "$TEST" = "WASM" ]; then PSP_DOCKER=1 yarn test --quiet; fi
  - if [ "$TEST" = "PYTHON" ]; then PSP_DOCKER=1 yarn build_python; fi
  - if [ "$TEST" = "PYTHON" ]; then PSP_DOCKER=1 yarn lint_python; fi
  - if [ "$TEST" = "PYTHON" ]; then PSP_DOCKER=1 yarn test_python; fi
  - if [ "$TEST" = "CPP" ]; then PSP_DOCKER=1 yarn build_cpp; fi
  - if [ "$TEST" = "CPP" ]; then PSP_DOCKER=1 yarn test_cpp; fi
  - if [ "$TEST" = "CPP_UBU14" ]; then yarn build_cpp; fi
  - if [ "$TEST" = "CPP_UBU14" ]; then yarn test_cpp; fi
  - if [ "$TEST" = "CPP_UBU16" ]; then yarn build_cpp; fi
  - if [ "$TEST" = "CPP_UBU16" ]; then yarn test_cpp; fi
  - if [ "$TEST" = "CPP_OSX" ]; then yarn build_cpp; fi
  - if [ "$TEST" = "CPP_OSX" ]; then yarn test_cpp; fi

The organization jpmorganchase was running a maximum number of jobs at the time (2019-01-30T18:16-0000), so additional jobs had to wait.