Compiler errors; Needs to be compiled with ISO C++ 2011 standard

[alinabee]

I wasn't able to compile because of the below error:
/usr/include/c++/5/bits/c++0x_warning.h:32:2: error: #error This file requires compiler and library support for the ISO C++ 2011 standard. This support must be enabled with the -std=c++11 or -std=gnu++11 compiler options.

Fixed by adding the following to CMakeLists.txt:

set (CMAKE_CXX_STANDARD 11)
target_link_libraries(hole_fixer pthread)