Honor pdftotree's loglevel when calling tabula

[HiromuHota]

Description of the problems or issues

Is your pull request related to a problem? Please describe.

See #101

Does your pull request fix any issue.

Close #101

Description of the proposed changes

Honor pdftotree's loglevel when calling tabula

Test plan

A clear and concise description of how you test the new changes.

Checklist

• I have updated the documentation accordingly.
• I have added tests to cover my changes.
• All new and existing tests passed.
• I have updated the CHANGELOG.md accordingly.

[HiromuHota]

pdftotree tests/input/paleo.pdf makes tabula silent and pdftotree tests/input/paleo.pdf -v does not.

When using pdftotree as a python module, pdftotree's logger needs to set its loglevel in order to make tabula silent, which is sort of cumbersome.

import pdftotree
import logging
log = logging.getLogger("pdftotree")
log.setLevel(logging.ERROR)
pdftotree.parse("tests/input/paleo.pdf")

[codecov-io]

Codecov Report

Merging #103 into master will increase coverage by 0.11%.
The diff coverage is 100.00%.

@@            Coverage Diff             @@
##           master     #103      +/-   ##
==========================================
+ Coverage   67.69%   67.80%   +0.11%     
==========================================
  Files          24       24              
  Lines        2600     2609       +9     
==========================================
+ Hits         1760     1769       +9     
  Misses        840      840              

Flag	Coverage Δ
unittests	67.80% <100.00%> (+0.11%)	⬆️

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Impacted Files	Coverage Δ
pdftotree/TreeExtract.py	89.29% <100.00%> (+0.03%)	⬆️
tests/test_basic.py	96.59% <100.00%> (+0.34%)	⬆️

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