fix travis.yml after changing Cargo.toml

.travis.yml

@@ -62,7 +62,7 @@ script:
   - if [ ${TRAVIS_RUST_VERSION} == "stable" -a "$TRAVIS_OS_NAME" = "linux" ]; then
     clang --version &&
     CARGO_TARGET_DIR=wasm cargo install --verbose --force wasm-pack &&
-    sed -i 's/\[lib\]/[lib]\ncrate-type = ["cdylib", "rlib"]/' Cargo.toml &&
+    printf '\n[lib]\ncrate-type = ["cdylib", "rlib"]\n' >> Cargo.toml &&
     CC=clang-9 wasm-pack build &&
     CC=clang-9 wasm-pack test --node;
     fi