29-Improve buildapi.py to handle kill signals

[phoenix-web3]

Description

There are some errors in the finalization of buildapi.py when you press Ctrl+C. We want to handle this signal to not show any exceptions.

Fixes #29 (issue)

Dependencies (if any)

Type of change

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)
• This change requires a documentation update

How Has This Been Tested?

1. Run python3 buildapy.py
2. Press Ctrl+C key to send SIGINT signal

OUTPUT:

~/projects/swapper/swapper-org/NodeChain/scripts$ python3 buildapi.py 
---------------------------------------------------
  _  _          _        ___  _                   
 | \| | ___  __| | ___  / __|| |_   __ _ (_) _ _  
 | .` |/ _ \/ _` |/ -_)| (__ | ' \ / _` || || ' \ 
 |_|\_|\___/\__,_|\___| \___||_||_|\__,_||_||_||_|
---------------------------------------------------
===================================================
                ENVIRONMENT SELECTION
===================================================
1.development
2.mainnet
3.testnet
4.Exit
Please choose the environment that you want to use to build up/stop the node(1-4): ^CExiting gracefully, goodbye!

Test Configuration:

• Operating system (output of cat /etc/os-release):

NAME="Ubuntu"
VERSION="18.04.5 LTS (Bionic Beaver)"
ID=ubuntu
ID_LIKE=debian
PRETTY_NAME="Ubuntu 18.04.5 LTS"
VERSION_ID="18.04"
VERSION_CODENAME=bionic
UBUNTU_CODENAME=bionic

• Kernel version (output of uname -sr): Linux 4.15.0-143-generic
• Architecture (output of uname -m): x86_64

Related PR or Docs PR

Docs PR related #
Other PR related #

Good practices to consider

• My code follows the style guidelines of this project
• I have performed a self-review of my own code
• I have commented my code, particularly in hard-to-understand areas
• I have made corresponding changes to the documentation
• My changes generate no new warnings
• I have added tests that prove my fix is effective or that my feature works
• New and existing unit tests pass locally with my changes
• Any dependent changes have been merged and published in downstream modules

[0xp3gasus]

We can merge this pull request. Thanks for your contribution