remove root requirements.txt (used one in docker directory).

requirements.txt

-asn1crypto==1.0.1
-blinker==1.4
-cffi==1.12.3
-Click==7.0
-cryptography==2.7
-Flask==1.1.1
-Flask-Login==0.4.1
-Flask-Mail==0.9.1
-Flask-SQLAlchemy==2.4.1
-itsdangerous==1.1.0
-Jinja2==2.10.3
-MarkupSafe==1.1.1
-pkg-resources==0.0.0
-pycparser==2.19
-six==1.12.0
-SQLAlchemy==1.3.13
-Werkzeug==0.16.0
-WTForms==2.2.1