Fixed errors in Duval Pentagon's areas

Fixed errors in Duval Pentagon's areas

v0.5: * Fixed error on Rogers Ratio FailureType calculation function

xDGA.CORE

• Fixed error on Rogers Ratio FailureType calculation function
• Updated README file and fixed typos

v0.4

xDGA.CORE

• Added Rogers Ratios algorithm

xDGA.ADDIN

• Added ROGERSRATIOS() funciton

v0.3

xDGA.CORE

• Implemented Pentagonal coordinate systems and transformation functions
• Implemented tests for every Duval Triangle and Pentagone Zone
• Added Duval Pentagons algorithm

xDGA.ADDIN

• Added DUVALPENTAGONS() function

v0.2

• Added Duval Triangles for Transformers, Reactors, Cables and On-Load Tap Changers
• Refactored some functions
• Added Failure Types (Codes and Descriptions) for OLTCs

v0.1

• First version released
• Includes two functions: SERIALIZEDGA() and IEC_60599()
• Uses ExcelDna and Json.NET