Add tasks flow

.travis.yml

@@ -4,8 +4,7 @@ python:
   - "3.6"
 
 script:
-  - cp README.md docs/index.md
+  - invoke build
-  - mkdocs build
 
 deploy:
   provider: pages

requirements.txt

@@ -1,2 +1,3 @@
 mkdocs==1.0.4
 mkdocs-material==4.5.0
+invoke

tasks.py

@@ -0,0 +1,9 @@
+import os
+from invoke import task, call
+
+
+@task
+def build(c):
+    """Build the website"""
+    c.run("cp README.md docs/index.md")
+    c.run("mkdocs build")