Properly handle semantic versioning in initialize_gradle_project

[michaelin]

The initialize_gradle_project function in utils.sh fails when the current Gradle version is a patch version (x.y.z):

vscode ➜ /workspaces/gradle-katas/build-phases (master ✗) $ ./setup.sh 
[KATA] Setting up the kata
[KATA] ------
[KATA] 
[KATA] Cleaning up old exercise
[KATA] Initializing new exercise
(standard_in) 1: syntax error
[KATA] Done!
vscode ➜ /workspaces/gradle-katas/build-phases (master ✗) $ gradle --version | grep Gradle | awk '{print $2}'
6.8.1

The problem is that bc can't compare semver version numbers. Consider using another tool or truncating the version before comparison.