ENH: Optimize nrows in read_excel
- [x] closes #32727
- [x] tests passed
- [x] passes `black pandas`
- [x] passes `git diff upstream/master -u -- "*.py" | flake8 --diff`
- [x] If header, skiprows and nrows are integers, rows that will be skipped are not loaded in get_sheet_data function. 

Tests which are not connected to that PR fail. But tests for readers already exist and include header, skiprows and nrows variables. Should I add something more? Mind fixing up the code checks @mproszewska and I agree with @mroeschke comments we should find a way to get rid of duplicate code  The CI is failing because of an unused import of _validate_integer Hello @mproszewska! Thanks for updating this PR. We checked the lines you've touched for [PEP 8](https://www.python.org/dev/peps/pep-0008) issues, and found:















There are currently no PEP 8 issues detected in this Pull Request. Cheers! :beers: 

##### Comment last updated at 2020-06-08 17:08:14 UTC I added suggested changes, but one test is still not passing and I'm not sure how to fix it. I removed skipping rows in openpyxl, because it seems like there is a problem with files leaking. It might be connected to [this](https://bitbucket.org/openpyxl/openpyxl/issues/673/workbook-context-manager#comment-36565768). Can you add a benchmark for this to show performance improvement? @mproszewska can you post the ASV results here as a comment? ```
[ 75.00%] ··· io.excel.ReadExcel.time_read_excel_nrows                                   ok
[ 75.00%] ··· ========== ===========
                engine              
              ---------- -----------
                 xlrd     1.92±0.1s 
               openpyxl   4.69±0.5s 
                 odf       11.3±1s  
              ========== ===========

[ 75.00%] · For pandas commit f0a4e8e5 <master> (round 2/2):
[ 75.00%] ·· Building for conda-py3.6-Cython0.29.16-matplotlib-numba-numexpr-numpy-odfpy-openpyxl-pytables-pytest-scipy-sqlalchemy-xlrd-xlsxwriter-xlwt...
[ 75.00%] ·· Benchmarking conda-py3.6-Cython0.29.16-matplotlib-numba-numexpr-numpy-odfpy-openpyxl-pytables-pytest-scipy-sqlalchemy-xlrd-xlsxwriter-xlwt
[100.00%] ··· Setting up io/excel.py:62                                                  ok
[100.00%] ··· io.excel.ReadExcel.time_read_excel_nrows                                   ok
[100.00%] ··· ========== ============
                engine               
              ---------- ------------
                 xlrd     2.11±0.08s 
               openpyxl   4.65±0.5s  
                 odf      14.5±0.1s  
              ========== ============
``` Can you fix merge master and fix merge conflicts? That may also fix CI

Can you post the output of a continuous asv run instead of just the snippet? It should provide results across multiple runs at the end @mproszewska can you address comments? Closing as I think this is stale but @mproszewska ping if you'd like to pick back up and can fix merge conflicts 