Custom Field build

This version builds on top of apex v1.0.0-rc3 and adds support for setting a concurrency value for a Lambda function in function.json like this:

{
    "name": "test",
    "description": "test concurrency",
    "runtime": "nodejs",
    "handler": "index.handle",
    "concurrency": 10
}

Install by downloading the correct version (i.e. replace linux with darwin if you're on a Mac) and putting the included binary into your /usr/local/bin directory:

$ curl -sSL https://github.com/fielded/apex/releases/download/v1.0.0-rc3.field/apex_linux_amd64.tar.gz | tar -xvz
apex_linux_amd64
$ sudo mv apex_linux_amd64 /usr/local/bin/apex
$ apex version
Apex version v1.0.0-rc3.field
$