Sat-ws

- Make sure that when constructing a `DateTime` it fails with an exception.
- Improve code coverage.

- Make `PackageReader\MetadataContent` tolerant to non-strict CSV contents:
- Ignore lead/inner/trail blank lines
- Include as `extra-%02d` any extra value (not listed in headers)
- Fill with empty strings if values are less than headers

Breaking changes:

- `CodeRequest::isNotFound` is replaced by `CodeRequest::isEmptyResult`
- `Fiel` has been rewritten with other dependences.
To create a Fiel object use any of this:
- `FielData::createFiel()`
- `Fiel::create($certificateContents, $privateKeyContents, $passPhrase)`
- XML SEC Signature now follow RFC 4514 on `X509IssuerName` node.
- Removed dependence to `eclipxe/cfdiutils`, it depends now on `phpcfdi/credentials`.

Other changes:

- Fix & improve composer/phpunit/travis/scrutinizer calls.
- Fix documentation typos.

Fist functional release