The secrets module should be used for generating cryptographically
strong random numbers suitable for managing data such as passwords,
account authentication, security tokens, and related secrets.

In particularly, secrets should be used in preference to the default
pseudo-random number generator in the random module, which is
designed for modelling and simulation, not security or cryptography.

(cherry picked from commit d21fd53)

(cherry picked from commit f398fdb)

* Added sphinx build for developers

Rationale is to build docs locally to prevent RTD to break later.

* Replace manual sphinx into make

* Renamed idan URL to oauthlib community

* Renamed http into https URLs since http is returning 302

* python requests library renamed its home URL

* Add ignore list for "make linkcheck"

linkcheck is doing requests to github with anonymous access, however creating an issue require an logged-in account

* virtualenv changed its homepage and website.

* Fixed broken link

(cherry picked from commit 32e5ad1)

(cherry picked from commit 66d7296)

Fixed grammar on line 7.