requirements: add requirements

Author: Kátia Nakamura

requirements.txt

@@ -1,9 +1,13 @@
 dj-database-url==0.5.0
 dj-static==0.0.6
 Django==1.11.11
+django-countries==5.3
+django-filter==1.1.0
+djangorestframework==3.8.2
 gunicorn==19.7.1
+Markdown==2.6.11
 Pillow==5.1.0
-psycopg2==2.7.4
+psycopg2-binary==2.7.4
 python-decouple==3.1
 pytz==2018.3
 static3==0.7.0