Call listeners before calling reporters

Catch2's documentation promises that listeners are called _before_
reporters, but because of the previous implementation, they were
called _after_ reporters. This commit fixes that.

Closes #1234

include/internal/catch_interfaces_reporter.h

@@ -226,8 +226,6 @@ namespace Catch {
         virtual Listeners const& getListeners() const = 0;
     };
 
-    void addReporter( IStreamingReporterPtr& existingReporter, IStreamingReporterPtr&& additionalReporter );
-
 } // end namespace Catch
 
 #endif // TWOBLUECUBES_CATCH_INTERFACES_REPORTER_H_INCLUDED