Fix SPHINCS+ clang-tidy warnings.

Reduce the number of test runs for Valgrind tests

Disable clang-tidy on i386

Fixed some buffer handling bugs that should never happen in practice

Add abstract state duplication for SHA256 incremental hashing API

This should drastically reduce the runtime of the valgrind tests

* Do tests with pytest to run them in parallel

* attempt to handle merge commits better for PR test path

Similar to how we solved this for travis

* Clean up imports

* don't run valgrind if not specified slow_test

* Fix functest after initializer rename

* upload tests results as junit

* Upload test-common files since #200 got merged

* Catch test results upload failure

* Move test support files into tests directory

* Fix common tests dir in test

* Fix Windows Makefile for common tests

* notrandombytes.obj should be in TEST_COMMON_DIR

Create SECURITY.md

Fix documentation for Dilithium `crypto_sign_open`

Only absorb root part of pk in haraka message hashing.

Add Rainbow

Falcon implementations (integer-only code, constant-time).

Uses the new Gitlab security documenting features/"standard" to explain our security non-policy.

It mentioned `sk` instead of `pk` as specified in the arguments.

Closes #205.

Make a static global in Frodo const

Document what exactly hash_state.h defines

Eliminate the global state

* Names passed around (mostly constant) value more clearly
* Put ``const`` where applicable (almost everywhere)
* Renamed ``primitive.h``
* Fixed some nits

This was causing compilation failures with clang, that there were 
duplicate const keywords once the macro was expanded in hash.h