Build Vault from code

Clone the official Vault repo and build a Vault binary from source code for your system.

Assumptions

Create a hashicorp source directory under your GOPATH and change to the new directory:
```
$ mkdir -p ${GOPATH}/src/hashicorp && cd $_
```

Clone the Vault repository from GitHub:

$ git clone https://github.com/hashicorp/vault.git

Change to the cloned Vault directory:
```
$ cd vault
```
Bootstrap the Go project to download and compile the libraries and tools needed to compile Vault:
```
$ make bootstrap
```
Use make to build Vault for your current system:
```
$ make dev
```
You can copy the compiled binary from ${GOPATH}/src/hashicorp/vault/bin/.

Create a hashicorp source directory under your GOPATH and change to the new directory:

New-Item -ItemType Directory -Force -Path "${env:GOPATH}/src/hashicorp" | Set-Location

Clone the Vault repository from GitHub:

git clone https://github.com/hashicorp/vault.git

Change to the cloned Vault directory:
```
Set-Location vault
```
Use the included make tool to bootstrap the Go project to download and compile the libraries and tools needed to compile Vault:
```
.\make bootstrap
```
Use the included make tool to build Vault for your current system:
```
.\make dev
```
You can copy the compiled binary from ${env:GOPATH}/src/hashicorp/vault/bin/.