Pull request from Shihan Silva

[merinosilva]

Hi,

In this pull request I have included the must-have fixes to the code.
Other than those fixes I would like to do the below changes to the code if it align with the company best practices and guidelines.

1. Change the project structure and add maven or gradle.
2. Add JUnit5 to the classpath and create test case in JUnit
3. Include classes in a package instead of keeping them in the default package
4. Change the method signature of getTollFee to accept LocalDateTime objects instead of Date objects

Additionally would like to integrate an external API or add a data setup to obtain the holiday list for each year.

Thanks,
Shihan Silva