Remove DeprecationWarning from using "+" operator

[AlexanderWells-diamond]

This used to be an easy way to return a copy of the array. Now we must use the explicit copy function.

Also removing an export for an enum that no longer exists.

[codecov[bot]]

Codecov Report

Merging #123 (565bca1) into master (63995ce) will not change coverage. The diff coverage is 100.00%.

@@           Coverage Diff           @@
##           master     #123   +/-   ##
=======================================
  Coverage   87.15%   87.15%           
=======================================
  Files          14       14           
  Lines         981      981           
=======================================
  Hits          855      855           
  Misses        126      126           

Impacted Files	Coverage Δ
softioc/device.py	95.60% <100.00%> (ø)
softioc/fields.py	86.11% <100.00%> (ø)

Help us with your feedback. Take ten seconds to tell us how you rate us. Have a feature suggestion? Share it here.

[github-actions[bot]]

Unit Test Results

     15 files  ±0       15 suites  ±0   27m 52s :stopwatch: -25s    249 tests ±0     243 :heavy_check_mark: ±0      6 :zzz: ±0  0 :x: ±0  3 735 runs  ±0  3 295 :heavy_check_mark: ±0  440 :zzz: ±0  0 :x: ±0 

Results for commit 565bca1f. ± Comparison against base commit 63995cef.