[Housekeeping] Bump Phoenix LiveView to 1.0.0 (#495)

* bumped liveview to 1.0.0

* Converted interpolation to new syntax

test/pinchflat/utils/string_utils_test.exs

@@ -41,4 +41,10 @@ defmodule Pinchflat.Utils.StringUtilsTest do
       assert StringUtils.truncate("hello", 10) == "hello"
     end
   end
+
+  describe "double_brace/1" do
+    test "wraps a string in double braces" do
+      assert StringUtils.double_brace("hello") == "{{ hello }}"
+    end
+  end
 end