Narrow types so we no longer have Vector{Any}

[pdeffebach]

Currently, if you call DataFrame on an AlphaVantageResponse object, you get a bunch of columns with eltype Any. This is kind of annoying, since each column really has the same type.

This fix here is a "quick fix", since we still allocate a Matrix{Any} at some point. But I don't want to add CSV.jl as a dependency. Not sure what the best strategy is long term.

[pdeffebach]

@ellisvalentiner can you confirm if test failures are part of this PR or unrelated?

[ellisvalentiner]

@pdeffebach thanks for the contribution

I think the test failures are due to how Github Actions handle secrets for forked pull requests.

[pdeffebach]

Okay let me add more tests.

Once the tests are added, and docs, we can merge this and think about how to get around readdlm issues in a future PR.

[ellisvalentiner]

@pdeffebach thanks, can you also bump the version number?

[pdeffebach]

Thank you! Sorry for not following up with this.

[dm13450]

No worries, thanks for doing the work!