Refactoring and moving classes for easier testing / scaling
Adding solution to problem 21
Merge branch 'master' of
https://github.com/jasper-vandemalle/project-euler.git

Conflicts:
	src/main/java/be/vandemalle/jasper/project/euler/ProblemTester.java
	src/main/java/be/vandemalle/jasper/project/euler/problems001to020/Problem001.java
	src/main/java/be/vandemalle/jasper/project/euler/problems001to020/Problem002.java
	src/main/java/be/vandemalle/jasper/project/euler/problems001to020/Problem003.java
	src/main/java/be/vandemalle/jasper/project/euler/problems001to020/Problem004.java
	src/main/java/be/vandemalle/jasper/project/euler/problems001to020/Problem005.java
	src/main/java/be/vandemalle/jasper/project/euler/problems001to020/Problem006.java
	src/main/java/be/vandemalle/jasper/project/euler/problems001to020/Problem007.java
	src/main/java/be/vandemalle/jasper/project/euler/problems001to020/Problem008.java
	src/main/java/be/vandemalle/jasper/project/euler/problems001to020/Problem009.java
	src/main/java/be/vandemalle/jasper/project/euler/problems001to020/Problem010.java
	src/main/java/be/vandemalle/jasper/project/euler/problems001to020/Problem011.java
	src/main/java/be/vandemalle/jasper/project/euler/problems001to020/Problem012.java
	src/main/java/be/vandemalle/jasper/project/euler/problems001to020/Problem013.java
	src/main/java/be/vandemalle/jasper/project/euler/problems001to020/Problem014.java
	src/main/java/be/vandemalle/jasper/project/euler/problems001to020/Problem015.java
	src/main/java/be/vandemalle/jasper/project/euler/problems001to020/Problem016.java
	src/main/java/be/vandemalle/jasper/project/euler/problems001to020/Problem017.java
	src/main/java/be/vandemalle/jasper/project/euler/problems001to020/Problem018.java
	src/main/java/be/vandemalle/jasper/project/euler/problems001to020/Problem019.java
	src/main/java/be/vandemalle/jasper/project/euler/problems001to020/Problem020.java
	src/test/java/be/vandemalle/jasper/project/euler/ProblemTest.java