Merge pull request #176 from sympy/use-datastore-remove-ndb

Use datastore directly and remove ndb

Merge pull request #170 from sympy/upgrade-sympy-162

Upgrade SymPy to 1.6.2

Merge pull request #166 from sympy/sympy-1-6-1

Upgrade SymPy to 1.6.1

Merge pull request #159 from sympy/upgrade-sympy-1

Upgrade SymPy to 1.6

Merge pull request #162 from sympy/sympy-version-in-footer

Show SymPy version in the footer

Merge pull request #154 from sympy/py3-runtime

Migrate to Python 3 runtime of Google App Engine

Merge pull request #153 from sympy/python-2-modernize

Modernize Python 2 code for migration to Python 3

Merge pull request #152 from sympy/remove-user-login

Remove user login feature and extract constants

Merge pull request #149 from sympy/dockerize

Dockerize the project for development

Merge pull request #149 from sympy/dockerize

Dockerize the project for development