Interop chain start strategies (#479)

* Implement more flexible beacon chain genesis

* Fix compile issues from rebase on master

* Rename CLI flag

* Adds initial documentation for TOML files

* Update docs readme

* Add first version of cli_util

* Dont write cache fields in serde

* Tidy cli_util

* Add code to load genesis YAML file

* Move serde_utils out of tests in `types`

* Update logging text

* Fix serde YAML for Fork

* Make yaml hex decoding more strict

* Update deterministic key generate for interop

* Set deposit count on testing genesis state

* Make some fixes for deposit count

* Remove code fragements

* Large restructure of docs

* Tidy docs

* Fix readme link

* Add interop docs

* Tidy README

docs/env.md

@@ -0,0 +1,52 @@
+# Development Environment Setup
+
+_This document describes how to setup a development environment. It is intended
+for software developers and researchers who wish to contribute to development._
+
+Lighthouse is a Rust project and [`cargo`](https://doc.rust-lang.org/cargo/) is
+used extensively. As such, you'll need to install Rust in order to build the
+project. Generally, Rust is installed using the
+[rustup](https://www.rust-lang.org/tools/install) tool-chain manager.
+
+## Steps
+
+A fully-featured development environment can be achieved with the following
+steps:
+
+   1. Install [rustup](https://rustup.rs/).
+   1. Use the command `rustup show` to get information about the Rust
+	  installation. You should see that the active tool-chain is the stable
+	  version.
+	  - Updates can be performed using` rustup update`, Lighthouse generally
+		  requires a recent version of Rust.
+   1. Install build dependencies (Arch packages are listed here, your
+   distribution will likely be similar):
+	  - `clang`: required by RocksDB.
+	  - `protobuf`: required for protobuf serialization (gRPC).
+	  - `cmake`: required for building protobuf
+	  - `git-lfs`: The Git extension for [Large File
+	    Support](https://git-lfs.github.com/) (required for Ethereum Foundation
+	    test vectors).
+   1. Clone the repository with submodules: `git clone --recursive
+	  https://github.com/sigp/lighthouse`.  If you're already cloned the repo,
+	  ensure testing submodules are present: `$ git submodule init; git
+	  submodule update`
+   1. Change directory to the root of the repository.
+   1. Run the test suite with `cargo test --all --release`. The build and test
+	  process can take several minutes. If you experience any failures on
+	  `master`, please raise an
+	  [issue](https://github.com/sigp/lighthouse/issues).
+
+## Notes:
+
+Lighthouse targets Rust `stable` but generally runs on `nightly` too.
+
+### Note for Windows users:
+
+Perl may also be required to build lighthouse. You can install [Strawberry
+Perl](http://strawberryperl.com/), or alternatively use a choco install command
+`choco install strawberryperl`.
+
+Additionally, the dependency `protoc-grpcio v0.3.1` is reported to have issues
+compiling in Windows. You can specify a known working version by editing
+version in `protos/Cargo.toml`  section to `protoc-grpcio = "<=0.3.0"`.