[Refacto] Fix kata romanNumerals module name

.gitignore

kata/romanNumerals/pom.xml

...nNumerals/src/main/java/fr/ippon/kata/roman/Numerals.java

...omanNumerals/src/main/java/fr/ippon/kata/roman/Roman.java

...erals/src/test/java/fr/ippon/kata/roman/NumeralsTest.java

pom.xml