Remove defaults and stop outputting fake data

[movermeyer]

What are you trying to accomplish?

Fixes #87. Removing defaults that would be incorrect if used.

What approach did you choose and why?

These commits remove unnecessary defaults. There are no instances of these attributes missing in the CLDR data, so there is no impact on the data exported by ruby-cldr.
In all but one case, the attributes are already required attributes (in the ldml.dtd schema), so there is no way they could be missing.

In the one case where the attribute is not a required attribute (type on dateTimeFormatLength), it was defaulting to a value that is not valid (:format). Once again, there are no current instances of a dateTimeFormatLength without a type attribute. In the rare case there were to ever be one, I'd rather have the export fail than silently pass with an invalid default value.

There are two instances in root where <alias> nodes were being handled incorrectly. Those keys are removed from the output by this change. See this comment for explanation.

What should reviewers focus on?

🤷

Note that this doesn't solve the problem of mixing number systems (#89).

The impact of these changes

• Gets rid of defaults that would be dangerous if they were used.
• Gets rid two incorrect data from root as a result of not following aliases.

Testing

You could run thor cldr:export for master and this branch, then run diff -r to compare the outputs:

git checkout master
thor cldr:export --target=./data_from_master

git checkout movermeyer:mo.stop_outputting_fake_data
thor cldr:export --target=./data_from_pr

diff -r data_from_master data_from_pr

Which outputs:

diff -r data_from_master/root/calendars.yml data_from_pr/root/calendars.yml
81,84d80
<         name:
<           0: ''
<         narrow:
<           0: ''

[movermeyer]

The root locale contains <alias> nodes for calendar eras:

• dates/calendars/calendar[8]/eras/eraNames/*
• dates/calendars/calendar[8]/eras/eraNarrow/*

These are incorrectly getting output as:

eras:
  abbr:
    0: BCE
    1: CE
  name:
    0: ''
  narrow:
    0: ''

Until #78 is addressed, I figure it is better not to output any data, rather than output incorrect data.