Add correct return type deduction for norm operations (#38)

12 jobs for master in 23 minutes and 5 seconds (queued for 3 seconds)
Status Job ID Name Coverage
  Static Test
passed clang-format #832146
clang elsa linux

00:00:16

passed clang-tidy #832147
clang elsa linux

00:00:24

 
  Compile
passed build-clang8 #832150
clang elsa linux

00:00:20

passed build-cuda92 #832151
cuda gcc elsa linux

00:00:25

passed build-gcc9 #832149
gcc elsa linux

00:00:21

passed build-ubuntu #832148
elsa linux

00:00:21

 
  Test
passed test-clang8 #832154
clang elsa linux

00:03:38

passed test-cuda92 #832155
cuda gcc elsa linux

00:03:52

passed test-gcc9 #832153
gcc elsa linux

00:03:51

passed test-ubuntu #832152
elsa linux

00:03:39

 
  Coverage
passed test-coverage #832156
cuda gcc elsa linux

00:17:57

97.0%
 
  Docs
passed deploy-docs #832157
elsa-docs-deploy

00:00:23