fix: fix leak in TreeSequence::dump_tables (#276)

Author: molpopgen

src/table_collection.rs

@@ -108,7 +108,7 @@ impl TableCollection {
         Ok(tables)
     }
 
-    fn new_uninit() -> Self {
+    pub(crate) fn new_uninit() -> Self {
         Self::wrap()
     }
 

src/trees.rs

@@ -1062,7 +1062,7 @@ impl TreeSequence {
     ///
     /// [`TskitError`] will be raised if the underlying C library returns an error code.
     pub fn dump_tables(&self) -> Result<TableCollection, TskitError> {
-        let mut copy = TableCollection::new(1.)?;
+        let mut copy = TableCollection::new_uninit();
 
         let rv = unsafe {
             ll_bindings::tsk_table_collection_copy((*self.as_ptr()).tables, copy.as_mut_ptr(), 0)