remove travis

.travis.yml

@@ -1,20 +0,0 @@
-language: python
-
-cache: pip
-
-python:
-  - '2.7'
-  - '3.6'
-
-matrix:
-  include:
-  - python: 3.7
-    dist: xenial
-    sudo: true
-
-install:
-  - pip install -U pip setuptools flake8
-
-script:
-  - python setup.py test
-  - flake8 disco/