bump version for 0.3.0.1 (#1353)

* bump version for 0.3.0.1

* fix mock versioning

* update welcome message

* remove old release note

Co-authored-by: Lucy Cifferello <12953208+elvece@users.noreply.github.com>

backend/src/version/v0_3_0_1.rs

@@ -0,0 +1,26 @@
+use emver::VersionRange;
+
+use super::*;
+
+const V0_3_0_1: emver::Version = emver::Version::new(0, 3, 0, 1);
+
+pub struct Version;
+#[async_trait]
+impl VersionT for Version {
+    type Previous = v0_3_0::Version;
+    fn new() -> Self {
+        Version
+    }
+    fn semver(&self) -> emver::Version {
+        V0_3_0_1
+    }
+    fn compat(&self) -> &'static VersionRange {
+        &*v0_3_0::V0_3_0_COMPAT
+    }
+    async fn up<Db: DbHandle>(&self, _db: &mut Db) -> Result<(), Error> {
+        Ok(())
+    }
+    async fn down<Db: DbHandle>(&self, _db: &mut Db) -> Result<(), Error> {
+        Ok(())
+    }
+}