Updates for deprecated numpy versions.

[HenryRWinterbottom]

Description

Using numpy to cast type has been deprecated in favor of using the native python functions (i.e. int(), float(), etc.).

Resolves #1725.

Type of change

Please delete options that are not relevant.

• Bug fix (non-breaking change which fixes an issue)

How Has This Been Tested?

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Checklist

• My code follows the style guidelines of this project
• I have performed a self-review of my own code
• I have commented my code, particularly in hard-to-understand areas
• My changes need updates to the documentation. I have made corresponding changes to the documentation
• My changes generate no new warnings
• New and existing tests pass with my changes

[aerorahul]

looks right.