Introduces selectors API for grouped fields

[kettanaito]

Change log

Touched

• Closes #289

Grouped fields schema selectors

• Closes #307
• Added new API to select grouped fields in validation schema selectors
• Validation algorithm adjusted to include grouped fields selectors as the highest priority ones
• Complementary nature of the validation schema resolvers remains as is
• Removed form.state.applicableRules
• Form now contains the relevant rules in its state (form.state.rules), which reacts to form.props.rules updates
• Determination of the relevant rules is delegated to the validation() invocations (the furthest point of calling the validation), to be aligned with the form state changes, and field changes
• Validation algorithm refactored, removed duplications, aligned to use a single getRulesPath() point to gather the selector keys from the schema

Minor

• Adds babel-plugin-ramda to reduce the bundle size
• Fixes #335

[kettanaito]

Updates dependencies after https://github.com/dominictarr/event-stream/issues/116. The malicious package is no longer present as any level dependency of react-advanced-form.

[kettanaito]

This should be published under the minor version (1.6). Therefore, the existing pull request for 1.6 will most likely be a subsequent release, or the next minor version.