Attempt at fixing Travis config for 1.17

.travis.yml

@@ -1,19 +1,29 @@
 language: rust
-script: cargo test --all-features $CARGOFLAGS
 
 jobs:
   include:
   - rust: 1.17.0
-    env: CARGOFLAGS="-p url"
+    install:
+    # --precise requires Cargo.lock to already exist
+    - cargo update
+    # getopts is only used in tests. Its versions 0.2.16+ don’t build on 1.17.0
+    - cargo update -p getopts --precise 0.2.15
+    # data-url uses pub(crate) which is unstable in 1.17
+    script: cargo test --all-features -p url -p idna -p percent-encoding -p url_serde
+
   - rust: stable
-    env: CARGOFLAGS="--all"
+    script: cargo test --all-features --all
+
   - rust: beta
-    env: CARGOFLAGS="--all"
+    script: cargo test --all-features --all
+
   - rust: nightly
-    env: CARGOFLAGS="--all"
+    script: cargo test --all-features --all
+
   - rust: nightly
-    env: CARGOFLAGS="--all --target=wasm32-unknown-unknown"
+    env: TARGET=WASM32  # For job list UI
     install: rustup target add wasm32-unknown-unknown
+    script: cargo build --all --target=wasm32-unknown-unknown
 
 notifications:
   webhooks: http://build.servo.org:54856/travis