Amico

* Fixed an issue where the call to `reciprocated?` in the internal method `add_following_followers_reciprocated` was not passing along the scope.

* Wrapped a few operations in Redis multi/exec blocks to be consistent with the rest of the library.

* Added `deny(from_id, to_id, scope = Amico.default_scope_key)` to remove a relationship that is pending between two IDs.

Again, thanks to [Skip Baney](https://github.com/twelvelabs) for the pull request with this functionality.

* Added `clear(id, scope = Amico.default_scope_key)` method to clear all relationships (in either direction) stored for an individual.

Added the following methods for the blocked by relationship:

* `blocked_by?(id, blocked_by_id, scope = Amico.default_scope_key)`
* `blocked_by(id, page_options = default_paging_options, scope = Amico.default_scope_key)`
* `blocked_by_count(id, scope = Amico.default_scope_key)`
* `blocked_by_page_count(id, page_size = Amico.page_size, scope = Amico.default_scope_key)`

Added the following methods for the pending with relationship:

* `pending_with?(id, blocked_by_id, scope = Amico.default_scope_key)`
* `pending_with(id, page_options = default_paging_options, scope = Amico.default_scope_key)`
* `pending_with_count(id, scope = Amico.default_scope_key)`
* `pending_with_page_count(id, page_size = Amico.page_size, scope = Amico.default_scope_key)`

Thanks to [Skip Baney](https://github.com/twelvelabs) for all the work on this release.

* Added `count(id, type, scope = Amico.default_scope_key)` and `page_count(id, type, page_size = Amico.page_size, scope = Amico.default_scope_key)` as convenience methods for retrieving the count or the page count for the various types of relationships.

* Added `Amico.all(id, type, scope)` to retrieve all of the individuals for a given id, type (e.g. following) and scope. Thanks to mettadore for the initial code and inspiration.
* Clarified parameters in following, followers, blocked, reciprocated, and pending calls.