Publish an alpha version of the Monero crate (#123)

* Label the version as an alpha

* Add versions to Cargo.tomls

* Update to Zeroize 1.5

* Drop patch versions from monero-serai Cargo.toml

* Add a repository field

* Move generators to OUT_DIR

IIRC, I didn't do this originally as it constantly re-generated them. 
Unfortunately, since cargo is complaining about .generators, we have to.

* Remove Timelock::fee_weight

Transaction::fee_weight's has a comment, "Assumes Timelock::None since 
this library won't let you create a TX with a timelock". Accordingly, 
this is dead code.

coins/monero/src/ringct/bulletproofs/original.rs

@@ -12,7 +12,7 @@ use multiexp::BatchVerifier;
 
 use crate::{Commitment, ringct::bulletproofs::core::*};
 
-include!("../../../.generators/generators.rs");
+include!(concat!(env!("OUT_DIR"), "/generators.rs"));
 
 lazy_static! {
   static ref ONE_N: ScalarVector = ScalarVector(vec![Scalar::one(); N]);

coins/monero/src/ringct/bulletproofs/plus.rs

@@ -15,7 +15,7 @@ use crate::{
   ringct::{hash_to_point::raw_hash_to_point, bulletproofs::core::*},
 };
 
-include!("../../../.generators/generators_plus.rs");
+include!(concat!(env!("OUT_DIR"), "/generators_plus.rs"));
 
 lazy_static! {
   static ref TRANSCRIPT: [u8; 32] =

coins/monero/src/transaction.rs

@@ -119,10 +119,6 @@ impl Timelock {
     }
   }
 
-  pub(crate) fn fee_weight() -> usize {
-    8
-  }
-
   fn serialize<W: std::io::Write>(&self, w: &mut W) -> std::io::Result<()> {
     write_varint(
       &match self {

coins/monero/src/wallet/mod.rs

@@ -167,6 +167,7 @@ impl Scanner {
   /// When a new scanner is created, ALL saved output keys must be passed in to be secure.
   /// If None is passed, a modified shared key derivation is used which is immune to the burning
   /// bug (specifically the Guaranteed feature from Featured Addresses).
+  // TODO: Should this take in a DB access handle to ensure output keys are saved?
   pub fn from_view(
     pair: ViewPair,
     network: Network,

coins/monero/src/wallet/scan.rs

@@ -196,8 +196,7 @@ impl SpendableOutput {
 pub struct Timelocked<O: Clone + Zeroize>(Timelock, Vec<O>);
 impl<O: Clone + Zeroize> Drop for Timelocked<O> {
   fn drop(&mut self) {
-    self.0.zeroize();
-    self.1.zeroize();
+    self.zeroize();
   }
 }
 impl<O: Clone + Zeroize> ZeroizeOnDrop for Timelocked<O> {}