Support extra args to tesseract

[timholy]

This allows one to pass additional command-line arguments to tesseract.
This makes it possible to exploit more of its functionality.

For example, in applications where layout is meaningful (e.g., screenshots),
retrieving the full TSV can be very useful.

[codecov]

Codecov Report

Merging #16 (d9fe231) into master (709e427) will decrease coverage by 0.07%.
The diff coverage is 100.00%.

@@            Coverage Diff             @@
##           master      #16      +/-   ##
==========================================
- Coverage   96.07%   96.00%   -0.08%     
==========================================
  Files           1        1              
  Lines          51       50       -1     
==========================================
- Hits           49       48       -1     
  Misses          2        2              

Impacted Files	Coverage Δ
src/tesseract.jl	96.00% <100.00%> (-0.08%)	⬇️

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[leferrad]

Thanks for your contribution @timholy! This is definitely a needed improvement to allow better usability 🙌

Give me a couple of days to check the changes better through a code review, also to understand why CI is failing for the nightly version. Once everything is OK we can merge and release a new version of the package.

[leferrad]

LGTM! Just a couple of suggestions / questions, then we are ok to approve 👌

[leferrad]

LTGM! CI is not working but for compatibility with the nightly version, which is out of the scope of this PR. So we can merge this, and then I proceed to prepare the release. Thanks again @timholy !

[timholy]

You surely noticed this, but the failure is ultimately due to SimpleMocking's use of Cassette. Cassette dives deep into Julia internals and is difficult to keep in working order, since the internal representation of code is deliberately not covered by the compatibility guarantee. To the extent that the failure bothers you, you could omit the mocking tests on Julia nightly?

[leferrad]

@timholy given I don't have the best solution in mind, I've created #21 to track this issue in order to figure out what to do.