Update README.md

Author: dbertolino-github

README.md

@@ -16,3 +16,5 @@ A tool to analyse Java code quality able to calculate the following metrics:
 
 The software is built on top of ANTLR4 compiler generated with an open-source Java8 grammar.
 It provides a JavaFX GUI and the possibility to print the results in three different .csv files, each one represents a depth level of the analysis: Overview, Classes and single methods.
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+This project is licensed under the terms of the Apache 2.0 License.