docs: add travis integration

.travis.yml

@@ -15,8 +15,8 @@ matrix:
             - debian-sid
           packages:
             - libssl-dev
-    - python 2.7
-      env: DOCS
+    - python: 2.7
+      env: DOCS=1
     - python: pypy
     - python: pypy
       env: OPENSSL=1.0.2
@@ -40,7 +40,8 @@ before_script:
   - "openssl version -a"
 
 script:
-  - "nosetests --with-cov --cov-report term-missing"
+  - "if [ -z \"$DOCS\" ]; then nosetests --with-cov --cov-report term-missing; fi"
+  - "if [ -n \"$DOCS\" ]; then cd docs && make html; fi"
 
 after_success:
   - coveralls
@@ -53,7 +54,7 @@ notifications:
     on_failure: always
   slack:
     rooms:
-        - mitmproxy:YaDGC9Gt9TEM7o8zkC2OLNsu
+      - mitmproxy:YaDGC9Gt9TEM7o8zkC2OLNsu
     on_success: change
     on_failure: always