Add test around (nonexistent) array fetch feature
Generalize test to include multidimensional arrays
Add array indexing to GetValue
update readme
Protect against runtime panic via array out-of-bounds error
Update README.
Merge branch 'tlehman-add-array-indexing'

* tlehman-add-array-indexing:
  Update README.
  Protect against runtime panic via array out-of-bounds error
  update readme
  Add array indexing to GetValue
  Generalize test to include multidimensional arrays
  Add test around (nonexistent) array fetch feature
  Fix installation instructions
Add changelog.
Refactor, better error messages.
Update changelog.