remove travis for gh actions

.travis.yml.disable

@@ -0,0 +1,21 @@
+language: python
+python:
+  - "3.5"
+  - "3.6"
+  - "3.7"
+  - "3.8"
+dist: focal
+install:
+  - "pip install pip --upgrade"
+  - "pip install -r tests-requirements.txt"
+  - "pip install -r requirements.txt"
+  - "npm install -g remark-cli remark-validate-links"
+  - "npm install -g markdown-link-check"
+script:
+  ./tests.sh
+after_success:
+  coveralls
+env:
+  global:
+    - DOTDROP_FORCE_NODEBUG=
+    - DOTDROP_NOBANNER=