Handle recognition errors in ruby parser

[abargnesi]

The ruby BEL parser will halt on the first error it encounters which makes handling large input problematic. Instead we should:

• capture recognition errors
• parse remaining characters until end of line
• continue with the next line's record

The BEL::Script.parse API should return errors back to the user.

[abargnesi]

Labeled as a bug because of its inconsistency with parsing in OpenBEL/openbel-framework.

[abargnesi]

Closed. See #122.