Identify options in AWS Texting SDK.

### Overview
If we are going to leverage the AWS Texting SDK we need to understand the capabilities so that we can design an effective process.

### Action Items

- [x] Identify differences in tiers for SDK
- [x] Determine what tier is needed to meet requirements below
- [ ] Identify Design/Development tasks necessary to integrate into MVP

Requirements:
- Coordinators need to be able to send text messages from the platform interface
- Guests and Hosts need to be able to reply to the coordinator from the message they received.
- Coordinators need to have new messages forwarded to their phone.
- Ex. if a guest messages that they will miss a meeting the host needs to have the info forwarded to them in the field.
- Coordinator Phone Number must always stay confidential.
- Coordinators need to be able to have hours of availability and away messages when they are not available.
- Guests/Hosts will need to be able to respond YES/NO; based on workflow, may have branching paths back to system

### Resources/Instructions
[Amazon Documentation](https://docs.aws.amazon.com/sdk-for-php/v3/developer-guide/sns-examples.html)