json config files

At the moment it seems that we need three config files:
- type.json define the types used in the plugin

```
["string", "integer", "email", "password",...]
```

These types are mapped to their html rendering tags
This file is private and only used by the abase plugin itself so it should be defined inside the plugin
- user-schema.json, define all the fields of the user stucture

```
{
"email": {"type": "email"},
"password": {"type": "password"},
"username": {"type": "string"},
...
}
```

This file is public and should be accessible by the user of the abase plugin like this she can add/remove fields of the user schema.
- page.json, define the pages and specifically which fields are displayed on a specific page

```
{
"register": {
"path": "/signup",
"type": "signup",
"method": [
"GET",
"POST"
],
"fields": [
{
"field": "email",
"type": "id",
"attributes": {
"name": "email",
"label": "Email: "
}
},
{
"field": "password",
"type": "password",
"attributes": {
"name": "password",
"label": "Password: "
}
}
]
},
"login": {
"path": "/login",
"type": "login",
"method": [
"GET",
"POST"
],
"fields": [
{
"field": "email",
"type": "id",
"attributes": {
"name": "email",
"label": "Email: "
}
},
{
"field": "password",
"type": "password",
"attributes": {
"name": "password",
"label": "Password: "
}
}
]
},
...
}
```

This file is also public and the user of the plugin can edit it.

So when the plugin is loaded for the first time it should:
- [x] load the user schema config (validate, add default fields email and password)
- [ ] load the pages config (validate, add default pages login, signup, list user, detail user, edit user)
- [ ] initialise the database with if it doesn't exist
- [x] create the routes from the pages config and create the handlers of these routes (imple

@eliascodes @shouston3 @jrans @nelsonic does this sound good for you? If yes I'm going to add the load page config feature (see issue #60 ). This means also that the user will need to pass in the option of the plugin the path of this page config file.