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
* Bump base64 from 0.9.3 to 0.10.0
* Bump bcrypt from 0.2.0 to 0.2.1
* Bump canapi from 0.1.0 to 0.2.0
* Bump failure from 0.1.2 to 0.1.3
* Bump hyper from 0.11.27 to 0.12.11
* Bump hyper from 0.11.27 to 0.12.16
* Bump lazy_static from 1.1.0 to 1.2.0
* Bump multipart from 0.15.3 to 0.15.4
* Bump openssl from 0.10.12 to 0.10.15
* Bump pulldown-cmark from 0.1.2 to 0.2.0
* Bump reqwest from 0.9.2 to 0.9.5
* Bump rocket from 0.4.0-rc.1 to 0.4.0
* Bump rpassword from 2.0.0 to 2.1.0
* Bump ructe from 0.5.2 to 0.5.4
* Bump serde_derive from 1.0.79 to 1.0.80
* Bump serde from 1.0.79 to 1.0.80
* Bump serde_json from 1.0.32 to 1.0.33
* Bump tera from 0.11.17 to 0.11.20
* Bump url from 1.7.1 to 1.7.2
* Bump validator to from 0.7.2 to 0.8.0
* Bump validator_derive from 0.7.2 to 0.8.0
* Bump whatlang from 0.5.0 to 0.6.0
* Remove hyper from plume-common dependencies
* Remove rpassword from Plume dependancies
* Upgrade compiler to nightly-2018-12-06
All the template are now compiled at compile-time with the `ructe` crate.
I preferred to use it instead of askama because it allows more complex Rust expressions, where askama only supports a small subset of expressions and doesn't allow them everywhere (for instance, `{{ macro!() | filter }}` would result in a parsing error).
The diff is quite huge, but there is normally no changes in functionality.
Fixes#161 and unblocks #110 and #273
