Fix Coverity RULE_OF_ZERO_THREE_FIVE issue

This also aligns with CppUTest change cpputest/cpputest@37735cc

Fixes:
```
lib/CppUTest/include/CppUTest/Failure.h:72:7:
  Type: Rule of three (RULE_OF_ZERO_THREE_FIVE)

lib/CppUTest/include/CppUTest/Failure.h:72:7:
  rule_of_three_violation: Class "EqualsFailure" has a user definition for at least one special function (copy constructor, copy assignment, destructor) but not all.  If one of these functions requires a user definition then the others likely do as well.
lib/CppUTest/include/CppUTest/Failure.h:80:2:
  copy_ctor: User-defined copy constructor.
lib/CppUTest/include/CppUTest/Failure.h:81:17:
  copy_assign: User-defined copy assignment operator.
lib/CppUTest/include/CppUTest/Failure.h:72:7:
  remediation: Add user-definition for a destructor.
```

Author: sophimao

lib/CppUTest/include/CppUTest/Failure.h

@@ -75,10 +75,6 @@ class EqualsFailure: public Failure
 
 	EqualsFailure(Utest*, const char* fileName, long lineNumber,
 			const SimpleString& expected, const SimpleString& actual);
-
-private:
-	EqualsFailure(const EqualsFailure&);
-	EqualsFailure& operator=(const EqualsFailure&);
 };
 
 class ContainsFailure: public Failure
@@ -87,10 +83,6 @@ class ContainsFailure: public Failure
 
 	ContainsFailure(Utest*, const char* fileName, long lineNumber,
 			const SimpleString& expected, const SimpleString& actual);
-
-private:
-	ContainsFailure(const ContainsFailure&);
-	ContainsFailure& operator=(const ContainsFailure&);
 };
 
 #endif