added TEST(getIdentityMatrix, MultiplyOfMatrixAndIdentityMatrixShouldReturnOriginalMatrix)
forgot to add exception class WrongSize
added specialization for template operator== with double parameters
fixed TEST(Invert, Matrix2x2)
added exception class DeterminantIsZero
added function AreAlmostEqual for comparison of doubles
at operator==() replaced long condition with comparison of two doubles with call of function areAlmostEqual()
at function getInvertedMatrix added condition that determinant must be not equal to zero
fixed TEST(Invert, Matrix2x2)
added TEST(getInvertedMatrix, MatrixWithDeterminantEqualsToZeroCantBeInverted), TEST(Invert, Matrix4x4)