Fixup installer generation

The installer pages need to be postprocessed a bit to have the latest
version on them, so this updates them to ensure that we're shipping the
postprocessed version at `/installer` instead of the raw versions

.gitignore

@@ -5,3 +5,4 @@ tests/bin
 wasm-pack.log
 /build-installer
 docs/book
+docs/installer

.travis.yml

@@ -60,7 +60,7 @@ matrix:
     - cargo install-update -a
     script:
     - (cd docs && mdbook build)
-    - rustc ./docs/installer/build-installer.rs
+    - rustc ./docs/_installer/build-installer.rs
     - ./build-installer
     deploy:
       provider: pages

docs/_installer/build-installer.rs

@@ -1,20 +1,20 @@
 use std::fs;
 
 fn main() {
-    fs::create_dir_all("docs/book/installer").unwrap();
+    fs::create_dir_all("docs/installer").unwrap();
     fs::copy(
+        "docs/_installer/wasm-pack.js",
         "docs/installer/wasm-pack.js",
-        "docs/book/installer/wasm-pack.js",
     ).unwrap();
-    let index = fs::read_to_string("docs/installer/index.html").unwrap();
+    let index = fs::read_to_string("docs/_installer/index.html").unwrap();
     fs::write(
-        "docs/book/installer/index.html",
+        "docs/installer/index.html",
         fixup(&index),
     ).unwrap();
 
-    let init = fs::read_to_string("docs/installer/init.sh").unwrap();
+    let init = fs::read_to_string("docs/_installer/init.sh").unwrap();
     fs::write(
-        "docs/book/installer/init.sh",
+        "docs/installer/init.sh",
         fixup(&init),
     ).unwrap();
 }