Resolve vulnerable packages

[Sid-Blommers]

Resolves two high reported vulnerabilities by Snyk.

Changes based on issue: #159

npm install currently requires the --legacy-peer-deps flag due to some version incompatibilities.

npm ERR! code ERESOLVE
npm ERR! ERESOLVE could not resolve
npm ERR! 
npm ERR! While resolving: [email protected]
npm ERR! Found: [email protected]
npm ERR! node_modules/jest
npm ERR!   dev jest@"^24.9.0" from the root project
npm ERR! 
npm ERR! Could not resolve dependency:
npm ERR! peer jest@">=26 <27" from [email protected]
npm ERR! node_modules/ts-jest
npm ERR!   dev ts-jest@"^26.3.0" from the root project
npm ERR! 
npm ERR! Conflicting peer dependency: [email protected]
npm ERR! node_modules/jest
npm ERR!   peer jest@">=26 <27" from [email protected]
npm ERR!   node_modules/ts-jest
npm ERR!     dev ts-jest@"^26.3.0" from the root project
npm ERR! 
npm ERR! Fix the upstream dependency conflict, or retry
npm ERR! this command with --force or --legacy-peer-deps
npm ERR! to accept an incorrect (and potentially broken) dependency resolution.