Related: simcaq/SCRUM#210 !31

SQL now is using new schema

- Mount route under '/api/v1/enrollment/location'
- It should list the location names for enrollments and school classes
- The reponse format is a lista of objects with each object having a location_id (CEBES014T1) and a description

Signed-off-by: João Victor Risso <joaovictor.risso@gmail.com>

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

Signed-off-by: João Victor Risso <joaovictor.risso@gmail.com>

Signed-off-by: João Victor Risso <joaovictor.risso@gmail.com>

Signed-off-by: João Victor Risso <joaovictor.risso@gmail.com>

- Add /location/educational/school_level route to query enrollments per school level;
- Add basic test case for the route. For now, it only checks if the format of the response is the expected one.

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

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

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

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

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

Change SQL queries in the following routes:

* city
* state
* region
* school
* enrollment

Also, change tests to reflect the new schema where appropriate. Specially in the case of cities, the primary key now becomes pk_cod_ibge (city IBGE code) and, therefore, any query that relies on the city id should use this value instead of the old primary key.

Aliases of fields that have different names were added to ensure compatibility with the UI of LDE.

Please refer to the database repository in order to understand how the current schema works. The corresponding ER diagram can be located there.

Sanitize the location in the result

Related: simcaq/SCRUM#68

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

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

Major modifications:
- Source code is now in the src directory
- All source files were adapted to ECMAScript6
- Add Gulpfile and Babel to transcompile the project from ES6 to ES5 (until Node.js fully supports ES6)
	- By running gulp one generates the build directory with the files transcompiled, from which the API can be run
- Add ESLint to check for syntax errors and enforce code standards
	- Javascript coding standard currently adopted is AirBnB with 4 spaces
- Replace monetdb package with monetdb-pool, which allows for concurrent queries over a pool of connections while maintaining the same interface

TODO (in order of priority, from high to low):
- Add Gulp tasks to handle automatic building, tests and running the server in order to deprecate using npm
- Implement decorator to execute the SQL queries and reduce code duplication.
- Implement SQL query builder (e.g. squel.js) to erradicate the need for embedding SQL directly into the code (which is error-prone).
- Change enrollments route not to use route chaining in order to decide which SQL query is appropriate to respond the user's request.
- Implement decorator for API responses and also reduce code duplication.
- Split up tests into and add more test cases.

Signed-off-by: João Victor Risso <jvtr12@c3sl.ufpr.br>