Updated the recommended rust nightly version

doc/Ecosystem.md

@@ -29,16 +29,16 @@ We suggest a Linux or OSX development environment, though Rust related tools are
 
 The [rustup](https://www.rustup.rs/), tool manager allows you to manage multiple tool chain installations. Rust is distributed in three channels (`stable`, `beta` and `nightly`). You may set the default toolchain:
 ```
-rustup default nightly-2017-10-22-x86_64-unknown-linux-gnu 
+rustup default nightly-2018-01-10-x86_64-unknown-linux-gnu 
 ```
 and get information on the status of `rustup`
 ```
 rustup show
 ```
 
-Nightly tool chains allow for the development of libraries and applications including `unsafe` code using features not available on the `stable channel` (which will be necessary for the later exercises). For some tools to work (`rls/rustfmt`), you need to install additional components. For this to work, you should use a nightly toolchain for which all tools and components work (currently `nightly-2017-10-30` is the latest). Here is an example:
+Nightly tool chains allow for the development of libraries and applications including `unsafe` code using features not available on the `stable channel` (which will be necessary for the later exercises). For some tools to work (`rls/rustfmt`), you need to install additional components. For this to work, you should use a nightly toolchain for which all tools and components work (currently `nightly-2018-01-10` is the latest). Here is an example:
 ```
-rustup default nightly-2017-10-30
+rustup default nightly-2018-01-10
 rustup component add rls-preview
 rustup component add rust-analysis
 rustup component add rust-src
@@ -71,7 +71,7 @@ Dependencies (may) include a minimal version, following the [semver](http://semv
 
 See [rls](https://marketplace.visualstudio.com/items?itemName=rust-lang.rust) for installing the RLS extension.
 
-You will need to pin the specific toolchain version used, by setting the `"rust-client.channel": "nightly-2017-10-30"` in your `vscode` *user* settings (this will be stored in a file `~/.config/Code/User/settings.json` and used for all your `vscode` projects. Settings may be set individually for each *workspace*, overriding the defaults. Regarding the  `"rust-client.channel"` setting, a *workspace* setting would force the specific version (overriding the default), and may not work when the code is distributed (as other developers may be on other toolchains).
+You will need to pin the specific toolchain version used, by setting the `"rust-client.channel": "nightly-2018-01-10"` in your `vscode` *user* settings (this will be stored in a file `~/.config/Code/User/settings.json` and used for all your `vscode` projects. Settings may be set individually for each *workspace*, overriding the defaults. Regarding the  `"rust-client.channel"` setting, a *workspace* setting would force the specific version (overriding the default), and may not work when the code is distributed (as other developers may be on other toolchains).
 
 For RLS to work, `vscode` need a path to the `rls-preview` library (using the environment variable `LD_LIBRARY_PATH` (Linux), `DYLD_LIBRARY_PATH` (OSX ?)). 
 ```