Reduce travis testing.

Travis seem to now have a lower limit on open-source builds; so reduce
dependency on Travis to get faster turnaround.

Will also limit the number of failures to 10, so that if there are many
test failing we don't spend too many cycles.

.travis.yml

@@ -1,123 +1,113 b''
 # http://travis-ci.org/#!/ipython/ipython
 language: python
 os: linux
 
 addons:
   apt:
     packages:
       - graphviz
 
 python:
-    - 3.6
+    - 3.8
 
 env:
   global:
     - PATH=$TRAVIS_BUILD_DIR/pandoc:$PATH
 
 group: edge
 
 before_install:
   - |
     # install Python on macOS
     if [[ "$TRAVIS_OS_NAME" == "osx" ]]; then
       env | sort
       if ! which python$TRAVIS_PYTHON_VERSION; then
         HOMEBREW_NO_AUTO_UPDATE=1 brew tap minrk/homebrew-python-frameworks
         HOMEBREW_NO_AUTO_UPDATE=1 brew cask install python-framework-${TRAVIS_PYTHON_VERSION/./}
       fi
       python3 -m pip install virtualenv
       python3 -m virtualenv -p $(which python$TRAVIS_PYTHON_VERSION) ~/travis-env
       source ~/travis-env/bin/activate
     fi
   - python --version
 
 install:
   - pip install pip --upgrade
   - pip install setuptools --upgrade
   - if [[ "$TRAVIS_PYTHON_VERSION" == "3.6" ]]; then
       echo "for the time being still test on 3.6";
       sed -ibkp s/7/6/g setup.py;
       git diff;
     fi
   - pip install -e file://$PWD#egg=ipython[test] --upgrade
   - pip install trio curio --upgrade --upgrade-strategy eager
-  - pip install 'pytest<6' 'matplotlib !=3.2.0' mypy
+  - pip install 'pytest<6' 'matplotlib !=3.2.0'
   - pip install codecov check-manifest pytest-cov --upgrade
-  - pip install mypy
-  - |
-    if [[ "$MASTER_DEPENDENCIES" == "True" ]]; then
-       pip install git+https://github.com/ipython/traitlets#egg=traitlets --force
-    fi
 
 
 script:
   - check-manifest
   - |
     if [[ "$TRAVIS_PYTHON_VERSION" == "nightly" ]]; then
        # on nightly fake parso known the grammar
        cp /home/travis/virtualenv/python3.9-dev/lib/python3.9/site-packages/parso/python/grammar38.txt /home/travis/virtualenv/python3.9-dev/lib/python3.9/site-packages/parso/python/grammar39.txt
     fi
   - |
     if [[ "$TRAVIS_PYTHON_VERSION" == "3.8" ]] && [[ "$TRAVIS_OS_NAME" == "linux" ]]; then
       cd /tmp && iptest --coverage xml && cd -
     fi
-  - pytest IPython
-  - mypy IPython/terminal/ptutils.py
-  - mypy IPython/core/c*.py
+  - pytest --maxfail=10 IPython
   # On the latest Python (on Linux) only, make sure that the docs build.
   - |
-    if [[ "$TRAVIS_PYTHON_VERSION" == "3.7" ]] && [[ "$TRAVIS_OS_NAME" == "linux" ]]; then
+    if [[ "$TRAVIS_PYTHON_VERSION" == "3.8" ]] && [[ "$TRAVIS_OS_NAME" == "linux" ]]; then
       pip install -r docs/requirements.txt
       python tools/fixup_whats_new_pr.py
       make -C docs/ html SPHINXOPTS="-W"
     fi
 
 after_success:
   - cp /tmp/ipy_coverage.xml ./
   - cp /tmp/.coverage ./
   - codecov
 
 matrix:
   include:
     - arch: amd64
       python: "3.6"
       dist: xenial
     - arch: amd64
       python: "3.7"
       dist: xenial
     - arch: amd64
       python: "3.8"
       dist: xenial
     - arch: amd64
       python: "nightly"
       dist: xenial
     - arch: amd64
       python: "3.9-dev"
     - os: osx
       language: generic
       python: 3.7
       env: TRAVIS_PYTHON_VERSION=3.7
-    - arch: amd64
-      python: "3.8"
-      env: MASTER_DEPENDENCIES=True
   allow_failures:
     - python: nightly
 
 before_deploy:
   - rm -rf dist/
   - python setup.py sdist
   - python setup.py bdist_wheel
 
 deploy:
   provider: releases
   api_key:
     secure: Y/Ae9tYs5aoBU8bDjN2YrwGG6tCbezj/h3Lcmtx8HQavSbBgXnhnZVRb2snOKD7auqnqjfT/7QMm4ZyKvaOEgyggGktKqEKYHC8KOZ7yp8I5/UMDtk6j9TnXpSqqBxPiud4MDV76SfRYEQiaDoG4tGGvSfPJ9KcNjKrNvSyyxns=
   file: dist/*
   file_glob: true
   cleanup: false
   on:
     repo: ipython/ipython
     all_branches: true  # Backports are released from e.g. 5.x branch
     tags: true
     python: 3.6  # Any version should work, but we only need one
     condition: $TRAVIS_OS_NAME = "linux"