Start reorg of per_epoch_processing

eth2/state_processing/src/per_epoch_processing/errors.rs

@@ -0,0 +1,36 @@
+use types::*;
+
+#[derive(Debug, PartialEq)]
+pub enum WinningRootError {
+    NoWinningRoot,
+    BeaconStateError(BeaconStateError),
+}
+
+#[derive(Debug, PartialEq)]
+pub enum EpochProcessingError {
+    UnableToDetermineProducer,
+    NoBlockRoots,
+    BaseRewardQuotientIsZero,
+    NoRandaoSeed,
+    BeaconStateError(BeaconStateError),
+    InclusionError(InclusionError),
+    WinningRootError(WinningRootError),
+}
+
+impl From<InclusionError> for EpochProcessingError {
+    fn from(e: InclusionError) -> EpochProcessingError {
+        EpochProcessingError::InclusionError(e)
+    }
+}
+
+impl From<BeaconStateError> for EpochProcessingError {
+    fn from(e: BeaconStateError) -> EpochProcessingError {
+        EpochProcessingError::BeaconStateError(e)
+    }
+}
+
+impl From<BeaconStateError> for WinningRootError {
+    fn from(e: BeaconStateError) -> WinningRootError {
+        WinningRootError::BeaconStateError(e)
+    }
+}