Added psycopg2 to requirements for postgresql support (installation needs python3-dev and libpg-dev

requirements.txt

-blinker==1.4
 Flask==0.10.1
 Flask-Login==0.2.11
 Flask-Passlib==0.1
 Flask-Principal==0.4.0
 Flask-SQLAlchemy==2.0
 Flask-WTF==0.12
-itsdangerous==0.24
 Jinja2==2.8
 MarkupSafe==0.23
-passlib==1.6.1
 SQLAlchemy==1.0.8
+WTForms==2.0.2
 Werkzeug==0.10.4
+blinker==1.4
+itsdangerous==0.24
+passlib==1.6.1
+psycopg2==2.6.1
 wheel==0.24.0
-WTForms==2.0.2