[BUG] PCN-iptables build failing

[acloudiator]

Describe the bug

Followed all the instructions to install the PCN-Iptables from https://github.com/polycube-network/polycube/blob/master/Documentation/installation.rst#installing-polycube-1
All goes well until I reach to the end section of the documentation link to install polycubed and polycubectl.

$ cmake .. -DENABLE_PCN_IPTABLES=ON
-- Version is pre_transparent_services+ [git: (branch/commit): master/79429777]
-- Latest recognized Git tag is -128-NOTFOUND
-- Git HEAD is 79429777c3b0afab3dc8770ed3b0b1b3bcac4558
-- Revision is 128-NOTFOUND-79429777
-- Found LLVM: /usr/lib/llvm-5.0/include 5.0.1
-- Using static-libstdc++
-- Could NOT find LuaJIT (missing: LUAJIT_LIBRARIES LUAJIT_INCLUDE_DIR)
CMake Warning at src/libs/bcc/tests/python/CMakeLists.txt:6 (message):
  Recommended test program 'arping' not found


CMake Warning at src/libs/bcc/tests/python/CMakeLists.txt:10 (message):
  ignore line: []
  ignore line: [Run Build Command:"/usr/bin/make" "cmTC_b4d5c/fast"]
  ignore line: [/usr/bin/make -f CMakeFiles/cmTC_b4d5c.dir/build.make CMakeFiles/cmTC_b4d5c.dir/build]
  ignore line: [make[1]: Entering directory '/home/kube/polycube/build/CMakeFiles/CMakeTmp']
  ignore line: [Building C object CMakeFiles/cmTC_b4d5c.dir/CMakeCCompilerABI.c.o]
  ignore line: [/usr/bin/cc    -o CMakeFiles/cmTC_b4d5c.dir/CMakeCCompilerABI.c.o   -c /usr/share/cmake-3.10/Modules/CMakeCCompilerABI.c]
  ignore line: [Linking C executable cmTC_b4d5c]
  ignore line: [/usr/bin/cmake -E cmake_link_script CMakeFiles/cmTC_b4d5c.dir/link.txt --verbose=1]
  ignore line: [/usr/bin/cc     -v -rdynamic CMakeFiles/cmTC_b4d5c.dir/CMakeCCompilerABI.c.o  -o cmTC_b4d5c ]
  ignore line: [Using built-in specs.]
  ignore line: [COLLECT_GCC=/usr/bin/cc]
  ignore line: [COLLECT_LTO_WRAPPER=/usr/lib/gcc/x86_64-linux-gnu/7/lto-wrapper]
  ignore line: [OFFLOAD_TARGET_NAMES=nvptx-none]
  ignore line: [OFFLOAD_TARGET_DEFAULT=1]
                                                                                                                                                                                              
  Recommended test program 'netperf' not found


CMake Error at /usr/share/cmake-3.10/Modules/FindPackageHandleStandardArgs.cmake:137 (message):
  Could NOT find PkgConfig (missing: PKG_CONFIG_EXECUTABLE)
Call Stack (most recent call first):
  /usr/share/cmake-3.10/Modules/FindPackageHandleStandardArgs.cmake:378 (_FPHSA_FAILURE_MESSAGE)
  /usr/share/cmake-3.10/Modules/FindPkgConfig.cmake:36 (find_package_handle_standard_args)
  src/polycubed/src/CMakeLists.txt:1 (find_package)


-- Configuring incomplete, errors occurred!
See also "/home/kube/polycube/build/CMakeFiles/CMakeOutput.log".

To Reproduce

Steps to reproduce the behavior:

1. Follow the instructions from https://github.com/polycube-network/polycube/blob/master/Documentation/installation.rst#installing-polycube-1
2. Execute the final section of the same doc to generate polycubed and polycubectl
3. See error and the output.log

Expected behavior

All the process should be clear and easy to follow without any error(s).

Please tell us about your environment:

1. OS details: Ubuntu 18.04 LTS
2. Kernel details: 4.15.0-20-generic x86_64
3. Polycube Version: N/A
4. Polycube Log: N/A

Additional context

n/A

[acloudiator]

Fixed in PR #145