title: No OCR tool found in python
body: <p>I have downloaded Mayan EDMS-Electronic Document Management System from GitHub and I configured project using Django server. I had added the required libraries based on requirement. Now the project runs with error </p>
  
  <pre><code>ocr.exceptions.OCRError: No OCR tool found
  </code></pre>
  
  <p>When I searched this error, I found  Pyocr looks for the OCR tools (Tesseract, Cuneiform, etc) installed on your system and just tells you what it has found.</p>
  
  <p>Then I tried to install tesseract using the command -->pip install tesseract-ocr.</p>
  
  <p>I got this error</p>
  
  <pre><code>    Requirement already satisfied: cython in ./venv2/lib/python2.7/site-packages (from tesseract-ocr) (0.28.4)
  running bdist_wheel
    running build
    running build_py
    file tesseract_ocr.py (for module tesseract_ocr) not found
    file tesseract_ocr.py (for module tesseract_ocr) not found
    running build_ext
    building 'tesseract_ocr' extension
    creating build
    creating build/temp.linux-x86_64-2.7
    x86_64-linux-gnu-gcc -pthread -DNDEBUG -g -fwrapv -O2 -Wall -Wstrict-prototypes -fno-strict-aliasing -Wdate-time -D_FORTIFY_SOURCE=2 -g -fdebug-prefix-map=/build/python2.7-l1RrwO/python2.7-2.7.14=. -fstack-protector-strong -Wformat -Werror=format-security -fPIC -I/usr/include/python2.7 -c tesseract_ocr.cpp -o build/temp.linux-x86_64-2.7/tesseract_ocr.o
    cc1plus: warning: command line option ‘-Wstrict-prototypes’ is valid for C/ObjC but not for C++
    tesseract_ocr.cpp:600:10: fatal error: leptonica/allheaders.h: No such file or directory
     #include "leptonica/allheaders.h"
  </code></pre>
  
  <p>please help me to solve this issue. Thanks in advance.</p>