Create pgr_areaContraction

[thisisashukla]

Create pgr_areaContraction function from template create.sh

• [x] Make a copy of create.sh as mycreate.sh
• [x] Change the new script to suit the function signature desired for pgr_areaContraction
  • pgr_areaContraction(sql, borderVerticesArray)
• [x] Generate new function directories using the modified script
• [x] Modify generated template files to suit the needs of the desired function
  • Modify sql\areaContraction\areaContraction.sql file
  • Modify src\areaContraction\src\areaContraction.c file
  • Modify drivers\areaContraction\areaContraction_driver.h file
  • Modify src\areaContraction\src\areaContraction_driver.cpp file
• [x] Rectify travis fail issues
• [x] Rectify Appveyor fail issues