New tests

Author: lpil

test/gleam/bit_builder_test.gleam

@@ -73,3 +73,9 @@ pub fn from_string_test() {
   |> bit_builder.to_bit_string
   |> should.equal(<<>>)
 }
+
+pub fn new_test() {
+  bit_builder.new()
+  |> bit_builder.to_bit_string
+  |> should.equal(<<>>)
+}

test/gleam/string_builder_test.gleam

@@ -100,3 +100,9 @@ pub fn is_empty_test() {
   |> string_builder.is_empty
   |> should.be_true
 }
+
+pub fn new_test() {
+  string_builder.new()
+  |> string_builder.to_string
+  |> should.equal("")
+}