Add support for detecting imported components

[gabmontes]

The import syntax is commonly used in the React/React Native community but the the split-platform-components rule does not capture errors when this pattern is used (#130).

This PR does the following:

• Update AST parsing to collect object assignment and import declarations.
• Update test suite.
• Update docs.

[coveralls]

Coverage increased (+0.5%) to 71.719% when pulling 688dfb9 on gabmontes:split_rule_parse_import into bd86879 on Intellicode:master.

[Intellicode]

Thanks for the PR! I'll do a new release shortly (tomorrow)