Move to gitsubmodules for dtu-core dependencies

.gitmodules

+[submodule "deps/dtu-enote-core"]
+	path = deps/dtu-enote-core
+	url = https://lab.compute.dtu.dk/enote/dtu-enote-core.git

Gemfile

@@ -6,7 +6,7 @@ gem 'activemodel', '~> 5.1.2'
 
 gem 'awesome_print'#, '~> 1.6', '>= 1.6.1'
 
-gem 'dtu-auth2', :path => '../dtu-core/dtu-auth2'
+gem 'dtu-auth2', :path => './deps/dtu-core/dtu-auth2'
 
 gem 'activesupport', '~> 5.1.2'
 

dtu-enote-core @ 601f75c4

+Subproject commit 601f75c4374ceceae3ba57e2f8bb5a9d81e658d2