Parachain auctions (#239)

* Slots module

* Integrate slots

* More drafting

* Minor updates

* Update parachains to use trati

* More build fixes

* Full code now compiles

* Add renew bid function

* Implement calculate_winner

* Warning remove

* Update gitignore

* Test framework

* Tests

* Further testing

* More tests, new parameterisation.

* Fix and new test

* Thread-safe tests

* Test off-boarding and a fix.

* Test onboarding

* Allow late onboarding.

* Another test and fix

* Avoid println in nostd

* Compact representation of paraids

* Introduce documentation.

* Introduce events.

* Additional test and fix

* Additional test

* Tidy up line lengths.

* Remove printlns

* Use later substrate utils.

* Fix build/test

* Make slots work with latest substrate

* Update runtime/src/slot_range.rs

Co-Authored-By: Robert Habermeier <rphmeier@gmail.com>

* Update runtime/src/slots.rs

Co-Authored-By: Shawn Tabrizi <shawntabrizi@gmail.com>

* Update runtime/src/slots.rs

Co-Authored-By: Shawn Tabrizi <shawntabrizi@gmail.com>

* Polish logic

* Rewind to earlier substrate master

* Remove dead code.

polkadot/runtime/src/claims.rs

@@ -50,6 +50,7 @@ impl EcdsaSignature {
 		r[64] = self.2 as u8;
 		r
 	}
+	#[cfg(test)]
 	pub fn from_blob(blob: &[u8; 65]) -> Self {
 		let mut r = Self([0u8; 32], [0u8; 32], 0);
 		r.0[..].copy_from_slice(&blob[0..32]);
@@ -148,7 +149,7 @@ mod tests {
 	use tiny_keccak::keccak256;
 	use super::*;
 
-	use sr_io::{self as runtime_io, with_externalities};
+	use sr_io::with_externalities;
 	use substrate_primitives::{H256, Blake2Hasher};
 	use codec::{Decode, Encode};
 	// The testing primitives are very useful for avoiding having to work with signatures