* Update plume-front build to use a shell script that adds the necessary dependencies on arm (x86 left untouched inside the script)
* Fix cleanup portion of plume-front.sh
* Break wasm dependencies for arm out so they are run before the main builds to improve layer caching on subsequent docker builds
* Fixup dockerfile so wasm-deps can run properly and with fewer assumptions
* Move new scripts to script/ folder
* Remove saving of path as it's not actually not necessary
* Add rust-toolchain to early copy so it pulls the right rust release (addresses #400)
Rust can compile to WASM, so let's use it for front-end code as well.
To compile the front-end:
```
cargo install cargo-web
cargo web deploy -p plume-front
```
* Remove use of String for body parameters
Create SignedJson and implement FromData for it
* Make Travis test on release
* Remove warning when installing and fix coverage
