Rename position

** *Warning: Merge #21 before you merge this* **

Status: **Opened for visibility**
Reviewers: **(GitHub @<name>s of all reviewers)**
JIRA: [{TICKET}](https://mobify.atlassian.net/browse/{TICKET})

## Changes
- Renamed all references to `position` 

## Notes
- We will likely want to come up with a naming scheme for effects to make them clear.