Remove travis config

.travis.yml

@@ -1,40 +0,0 @@
-sudo: false
-language: python
-dist: trusty
-matrix:
-  include:
-    #
-    # Python 3.6 testing
-    #
-    # core
-    - python: "3.6"
-      env: TOX_POSARGS="-e py36-core"
-    # lint
-    - python: "3.6"
-      env: TOX_POSARGS="-e lint"
-    # doctest
-    - python: "3.6"
-      env: TOX_POSARGS="-e doctest"
-    #
-    # Python 3.7 testing
-    #
-    # core
-    - python: "3.7"
-      env: TOX_POSARGS="-e py37-core"
-    #
-    # pypy3 testing
-    #
-    # core
-    - python: "pypy3.5"
-      env: TOX_POSARGS="-e pypy3-core"
-cache:
-  - pip: true
-install:
-  - travis_retry pip install pip setuptools --upgrade
-  - travis_retry pip install tox
-before_script:
-  - python --version
-  - pip --version
-  - pip freeze
-script:
-  - tox $TOX_POSARGS