move handler_test.go to internal/server package

[eric-jacobson]

By submitting this pull request, I confirm that my contribution is made under the terms of the MIT license.

Problem/Feature

Resolves #280

Description of Changes:

• moved handler_test.go to internal/server package and renamed to routes_test.go
• updated docs referring to handler_test.go in the previous location

Checklist

• I have self-reviewed the changes being requested
• I have updated the documentation (check issue ticket 📋Update documentation if the PR introduces a new feature!📋 #218)

[Ujstor]

This looks good. Thanks for solving the open issue. Only make test needs to be updated.

test:
	@echo "Testing..."
-	@go test ./tests -v
+	@go test ./... -v

[eric-jacobson]

This looks good. Thanks for solving the open issue. Only make test needs to be updated.

test:
	@echo "Testing..."
-	@go test ./tests -v
+	@go test ./... -v

Good catch! Updated that as well as the makefile.md doc

[Ujstor]

LGTM