Feature/load otp data

Took me a while to figure out what was going on. The relative path is on the virtual machine host and needs to go backwards from the current role's directory, right?

One of these Ansible variables might make generating the path a littler cleaner:

- `playbook_dir`
- `inventory_dir`
- `inventory_file`

I ran these locally and they produced the follow results:

**Playbook**:

```yaml
- debug: msg="{{ playbook_dir }}"

- debug: msg="{{ inventory_dir }}"

- debug: msg="{{ inventory_file }}"
```

**Output**:

```
TASK: [nyc-trees.app | debug msg="/Users/hcastro/Projects/nyc-trees/deployment/ansible"] ***
ok: [app] => {
    "msg": "/Users/hcastro/Projects/nyc-trees/deployment/ansible"
}

TASK: [nyc-trees.app | debug msg="/Users/hcastro/Projects/nyc-trees/deployment/ansible/inventory"] ***
ok: [app] => {
    "msg": "/Users/hcastro/Projects/nyc-trees/deployment/ansible/inventory"
}

TASK: [nyc-trees.app | debug msg="deployment/ansible/inventory/test"] *********
ok: [app] => {
    "msg": "deployment/ansible/inventory/test"
}
```

Maybe create a top-level `gtfs_dir` variable that uses `playbook_dir` with some manipulation and then have an `otp_gtfs_dir` that just gets set to `gtfs_dir`?