[login-student] Fazendo o login/logout do estudante com o devise

Signed off by: Jackson J Souza <jacksonjsouza@gmail.com>
[login-student] Colocando os links para login/logout de alunos no menu

Signed off by: Jackson J Souza <jacksonjsouza@gmail.com>
[login-student] Colocando as permissões para os metodos do controller do aluno

Signed off by: Jackson J Souza <jacksonjsouza@gmail.com>
[login-student] Colocando links e permissões nas views

Signed off by: Lucas Takeshi <lucastakeshipalma@gmail.com>
[login-student] Arrumando e criando testes de rspec

Signed off by: Lucas Takeshi <lucastakeshipalma@gmail.com>
[login-student]  Adicionados testes de aceitação para o crud e login do aluno

Signed off by: Wilson Kazuo Mizutani <kazuo256@gmail.com>
Signed off by: Lucas Takeshi <lucastakeshipalma@gmail.com>
[login-student] Arrumando testes após rebase

Signed off by: Wilson Kazuo Mizutani <kazuo256@gmail.com>
Signed off by: Lucas Takeshi <lucastakeshipalma@gmail.com>