- Default config file config.json now is gitignored
- Created config.json.example

add mongodb + mongoose and setup db config

Instalação do MongoDB:
1. Baixar arquivos no link http://mongodb.org/downloads.
2. Extrair os arquivos.
3. Criar o diretório de armazenamento dos BDs (default location is **/data/db**) com $ mkdir -p /data/db
4. sudo chown -R $USER /data/db

Para rodar o banco, basta ir até a pasta **bin** do arquivo baixado e rodar o binário **mongod**

Para usar o shell do MongoDB, basta ir até a pasta **bin** do arquivo baixado e rodar o binário **mongo**


See merge request !12

Add school route

Add school routes:

* `/school/:id`: get a school by its identifier
* `/school/state/:id`: get all schools from a state
* `/school/city/:id`: get all schools from a city

See merge request !11

Missing .toParam() method in squel

Cache lasts for a day

All routes now use squel and the sql, query, response chain

Refactor enrollments route to include query building

Changes:
- Add error handling in the database query function. When a database error
occurs, it is logged in the server and a plain text response is returned to the
user.
- Implement building of SQL queries inside the API, which removes the
  need to have stored functions/procedures on the database, since the former
approach is not flexible or efficient to maintain/extend.
- Use route chaining to determine which function will build the query
  that needs to be executed. The last function is the one that actually
  sends the query to the database and send the response.

Future Work:
- Instead of returning a plain text response, return a HTTP 501 status,
  which is currently not possible. When one attempts to send such status
  the framework throws an error that the headers were already sent for
  the current request.
- Chaining based on the route might not be the best solution here.

See merge request !7

Signed-off-by: João Victor Tozatti Risso <jvtr12@inf.ufpr.br>