Add a Node (#22)

* Copy node-template over from Substrate repo

Got the template at rev=6e6d06c33911

* Use dependencies from crates.io + stop renaming on import

* Remove template pallet

* Stop using crates.io dependencies

Instead they're going to be pinned at v2.0.0-alpha.2
at commit `2afecf81ee19b8a6edb364b419190ea47c4a4a31`
until something stable comes along.

* Remove LICENSE

* Change references of `node-template` to `bridge-node`

* Remove README

* Fix some missed node-template references

* Add WASM toolchain to CI

* Be more specific about nightly version to use

* Maybe don't tie to a specific nightly

* Use composite accounts

* Update to use lazy reaping

* Only use Development chain config