Add sqlite binary into the docker images

This is done to enable backup functionality in the admin interface while
we're waiting for the libsqlite-sys 0.17 to bubble up in the upstream
dependencies. Then we can start using `VACUUM INTO`

This also extends the check for the sqlite binary to also try `sqlite3`
as this is the name of the binary in baseimage distributions we use.

src/api/admin.rs

@@ -37,7 +37,11 @@ pub fn routes() -> Vec<Route> {
 }
 
 lazy_static! {
-    static ref CAN_BACKUP: bool = cfg!(feature = "sqlite") && Command::new("sqlite").arg("-version").status().is_ok();
+    static ref CAN_BACKUP: bool = cfg!(feature = "sqlite") && 
+    ( 
+        Command::new("sqlite").arg("-version").status().is_ok() ||
+        Command::new("sqlite3").arg("-version").status().is_ok()
+    );
 }
 
 #[get("/")]