Let Travis test both beta and nightly

.travis.yml

@@ -1,5 +1,11 @@
 language: rust
 
+rust:
+    - 1.0.0-beta
+    - nightly
+
+sudo: false
+
 notifications:
     email:
         on_success: never
@@ -9,13 +15,11 @@ env:
     global:
         - secure: "VeXvD0tLJyu38t87p8AAztSQVBxsCE1y016l/Nc44203V/RUxj4tz5ifaZcKziPqFHK2ITs2T6fBE1uu404zMVwA0W0J8vmG6+xDoJJLsbwKp4W3SlAI+oIEmFSTIxgzAB7hio17VPDmAqKbnbhbmbP+U94ygoztRNN3ObCZ8yo="
 
-sudo: false
-
 script:
-- cargo build
-- cargo test
-- cargo doc --no-deps
-- rustdoc --test README.md -L target
+    - cargo build
+    - cargo test
+    - cargo doc --no-deps
+    - rustdoc --test README.md -L target
 
 after_success:
-- .travis/publish_doc.sh
+    - .travis/publish_doc.sh

.travis/publish_doc.sh

@@ -2,7 +2,8 @@
 
 if  [ "$TRAVIS_BRANCH" = "master" ] &&
     [ "$TRAVIS_PULL_REQUEST" = "false" ] &&
-    [ "$TRAVIS_REPO_SLUG" = "mvdnes/zip-rs" ]
+    [ "$TRAVIS_REPO_SLUG" = "mvdnes/zip-rs" ] &&
+    [ "$TRAVIS_RUST_VERSION" = "1.0.0-beta" ]
 then
     echo "Publishing documentation..."