Update raven and some other general improvements

[adambiggs]

In this PR

• Updated raven to the latest version
• Changed from underscore to lodash
• Store all default options in this.defaults object
• Merge user options with defaults using lodash _.defaultsDeep() for compatibility with future raven features

  Breaking Change

All options passed to winston-sentry now mirror those used by raven. This means the previous globalTags option is now named tags.

[grimurd]

@guzru @shaharke Can somebody take a look at this PR and merge it?

[shaharke]

@adambiggs I like the refactoring. Notice that this change is not backwards compatible since globalTags is ignored. I suggest we make it backwards compatible before merging.

[adambiggs]

@shaharke the reason for the breaking change is that options are now passed directly to the raven client. So the winston-sentry options API should match raven's API.

The advantage is that new options added to raven in future releases should "just work" without any additions to winston-sentry.

[shaharke]

@adambiggs I understand, but that would break users' code. The need to move globalTags into tags.

[adambiggs]

@shaharke ok, how about if i add something like options.tags = options.tags || options.globalTags for backward compatibility.

[shaharke]

@adambiggs published as 0.1.2

[adambiggs]

Thanks! 🍻