WIP : Code refactoring

[chfw]

With your PR, here is a check list:

• [ ] Has Test cases written
• [x] Has all code lines tested
• [x] Has make format been run?
• [ ] Please update CHANGELOG.yml(not CHANGELOG.rst)
• [x] Passes all Travis CI builds
• [x] Has fair amount of documentation if your change is complex
• [x] run 'make format' so as to confirm the pyexcel organisation's coding style
• [ ] Please add yourself to 'contributors' section of pyexcel-io.yml (if not found, please use CONTRIBUTORS.rst)
• [ ] Agree on NEW BSD License for your contribution

[codecov-commenter]

Codecov Report

Merging #77 into dev will increase coverage by 0.88%. The diff coverage is 99.03%.

@@            Coverage Diff             @@
##              dev      #77      +/-   ##
==========================================
+ Coverage   95.54%   96.43%   +0.88%     
==========================================
  Files          51       51              
  Lines        3303     3229      -74     
==========================================
- Hits         3156     3114      -42     
+ Misses        147      115      -32     

Impacted Files	Coverage Δ
pyexcel_io/readers/__init__.py	100.00% <ø> (ø)
pyexcel_io/readers/csv_sheet.py	95.32% <ø> (ø)
tests/test_service.py	100.00% <ø> (+4.81%)	:arrow_up:
pyexcel_io/readers/tsv.py	93.33% <90.90%> (+11.51%)	:arrow_up:
pyexcel_io/_compact.py	64.28% <100.00%> (+6.14%)	:arrow_up:
pyexcel_io/plugins.py	96.29% <100.00%> (-0.04%)	:arrow_down:
pyexcel_io/reader.py	97.40% <100.00%> (+0.10%)	:arrow_up:
pyexcel_io/readers/csv_content.py	100.00% <100.00%> (ø)
pyexcel_io/readers/csv_in_file.py	96.87% <100.00%> (ø)
pyexcel_io/readers/csv_in_memory.py	97.22% <100.00%> (ø)
... and 14 more

---

Continue to review full report at Codecov.

Legend - Click here to learn more Δ = absolute <relative> (impact), ø = not affected, ? = missing data Powered by Codecov. Last update 4bc78d6...69644a6. Read the comment docs.