test: add unit tests for RecipeController

Covers 6/6 methods in controller
Also added test configuration in application-mock-data-test.properties

server/src/main/resources/application-mock-data-test.properties

@@ -0,0 +1,18 @@
+spring.datasource.driverClassName=org.h2.Driver
+spring.datasource.username=sa
+spring.datasource.password=
+spring.jpa.database-platform=org.hibernate.dialect.H2Dialect
+
+# use one of these alternatives...
+# ... purely in-memory, wiped on restart, but great for testing
+spring.datasource.url=jdbc:h2:mem:testdb
+# ... persisted on disk (in project directory)
+#spring.datasource.url=jdbc:h2:file:./h2-database
+
+# enable DB view on http://localhost:8080/h2-console
+spring.h2.console.enabled=true
+
+# strategy for table (re-)generation 
+spring.jpa.hibernate.ddl-auto=update
+# show auto-generated SQL commands
+#spring.jpa.hibernate.show_sql=true