Try cache speed up trick

.travis.yml

@@ -5,14 +5,15 @@ branches:
     - master
     - travis
 
-language: rust
-
 dist: trusty
+language: rust
 sudo: false
 addons:
   chrome: stable
 
 cache: cargo
+before_cache:
+  - ./ci/clear_cache.sh
 
 rust:
   - 1.35.0 # min supported

ci/check_examples.sh

@@ -8,3 +8,5 @@ cargo web build --target asmjs-unknown-emscripten
 cargo web build --target wasm32-unknown-emscripten
 # TODO showcase doesn't support wasm-bindgen yet
 cargo web build --target wasm32-unknown-unknown
+# Reset cwd
+cd ../..

ci/clear_cache.sh

@@ -0,0 +1,22 @@
+#!/usr/bin/env bash
+set -x
+
+# inspired by https://github.com/rust-analyzer/rust-analyzer/blob/master/.travis.yml
+find ./target/debug -maxdepth 1 -type f -delete
+find ./target/tests/target/debug -maxdepth 1 -type f -delete
+find ./target/asmjs-unknown-emscripten/debug -maxdepth 1 -type f -delete
+find ./target/wasm32-unknown-emscripten/debug -maxdepth 1 -type f -delete
+find ./target/wasm32-unknown-unknown/debug -maxdepth 1 -type f -delete
+rm -fr ./target/debug/{deps,.fingerprint}/{*yew*,*\.was,*\.js*,*test*}
+rm -fr ./target/tests/target/debug/{deps,.fingerprint}/{*yew*,*\.was,*\.js*,*test*}
+rm -fr ./target/asmjs-unknown-emscripten/debug/{deps,.fingerprint}/{*yew*,*\.was,*\.js*,*test*}
+rm -fr ./target/wasm32-unknown-emscripten/debug/{deps,.fingerprint}/{*yew*,*\.was*,*\.js*,*test*}
+rm -fr ./target/wasm32-unknown-unknown/debug/{deps,.fingerprint}/{*yew*,*\.was*,*\.js*,*test*}
+rm -fr ./target/debug/incremental
+rm -fr ./target/tests/target/debug/incremental
+rm -fr ./target/asmjs-unknown-emscripten/debug/incremental
+rm -fr ./target/wasm32-unknown-emscripten/debug/incremental
+rm -fr ./target/wasm32-unknown-unknown/debug/incremental
+rm -f  ./target/.rustc_info.json
+rm -f  ./target/tests/target/.rustc_info.json
+rm -fr ./target/wasm32-unknown-unknown/wbg-tmp