First pre-release that passes all SHACL-core tests

New features

• Passes all SHACL-Core tests

• Implements most ShEx features except semantic actions which are partially implemented

TODOs

• ShEx: Complete semantic actions implementation Issue 116

• ShEx: test-suite with shape maps and update report Issue 115

• Shaclex: Conversion from ShEx to SHACL Issue 114

• Shaclex: Conversion from SHACL to ShEx Issue 113

• Shacl: Implement SHACL-Sparql Issue 112