Make url and list name consistent. Fix #12

Make the url stored always be the same regardless if the user
entered with or without trailing slash.  Also takes care or giving
the list alias (or name) a meaningful text (non-empty) as much
as possible.

Add testcases for the class MailingList, which handles the
location, mailing list name, etc.

Signed-off-by: Santiago Dueñas <sduenas@bitergia.com>
Use get_database instead of create database
dbn: Add new database module/definition using SqlAlchemy
dbn: Add session implementation to integrate the new database
dbn: Add class Report for generating reports from the database
Integration of SqlAlchemy classes in mlstats
ci: Update .travis.yml for continuous integration
dbn: Remove unused methods
Remove old database code
db: Move new database implementation in the old namespace

Last step to replace the old database implementation with
SqlAlchemy
db: Force convert to unicode for MySQL dialect
Simplify logging information
Remove admin parameters to the create database

Since SqlAlchemy, we will rely on the user to create the
database, though we will create the tables if they don't
exists. Therefore, this option does not makes sense anymore.
tests: Update tests according to latest changes in analyzer

We now returns a datetime instead of a ISO string, therefore,
the test should reflect that comparison