Update formating (using clang-format-9)

src/algebra/TinyMatrix.hpp

@@ -20,7 +20,8 @@ class TinyMatrix
   static_assert((N > 0), "TinyMatrix size must be strictly positive");
 
   PUGS_FORCEINLINE
-  constexpr size_t _index(const size_t& i, const size_t& j) const noexcept   // LCOV_EXCL_LINE (due to forced inline)
+  constexpr size_t
+  _index(const size_t& i, const size_t& j) const noexcept   // LCOV_EXCL_LINE (due to forced inline)
   {
     return i * N + j;
   }