Fix #23, Moves interface definition files to inc

[chillfig]

Checklist (Please check before submitting)

• I reviewed the Contributing Guide.
• I signed and emailed the appropriate Contributor License Agreement to GSFC-SoftwareRelease@mail.nasa.gov and copied cfs-program@lists.nasa.gov.

Describe the contribution

• Fixes #57

Testing performed
No testing performed.

Expected behavior changes
No expected behavior change.

System(s) tested on
-Ubuntu 18.04

Additional context
#5 remains unaddressed ?

Third party code
If included, identify any third party code and provide text file of license

Contributor Info - All information REQUIRED for consideration of pull request
-Justin Figueroa, Vantage

[chillfig]

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