add support for inequalities

include/internal/catch_approx.hpp

@@ -58,6 +58,26 @@ namespace Detail {
             return !operator==( rhs, lhs );
         }
 
+        friend bool operator <= ( double lhs, Approx const& rhs )
+        {
+          return lhs < rhs.m_value || lhs == rhs;
+        }
+
+        friend bool operator <= ( Approx const& lhs, double rhs )
+        {
+          return lhs.m_value < rhs || lhs == rhs;
+        }
+
+        friend bool operator >= ( double lhs, Approx const& rhs )
+        {
+          return lhs > rhs.m_value || lhs == rhs;
+        }
+
+        friend bool operator >= ( Approx const& lhs, double rhs )
+        {
+          return lhs.m_value > rhs || lhs == rhs;
+        }
+
         Approx& epsilon( double newEpsilon ) {
             m_epsilon = newEpsilon;
             return *this;