Sync latest updates from submodules to works/ directory.

diff --git a/works-tmp/palindrome-checker b/works-tmp/palindrome-checker
new file mode 160000 (submodule)
index 0000000..e8449e2
--- /dev/null
+++ b/works-tmp/palindrome-checker
@@ -0,0 +1 @@
+Subproject commit e8449e21868dcdccd581d3db3df491e53cbdd69c

diff --git a/works-tmp/roman-numeral-converter b/works-tmp/roman-numeral-converter
new file mode 160000 (submodule)
index 0000000..2457a3a
--- /dev/null
+++ b/works-tmp/roman-numeral-converter
@@ -0,0 +1 @@
+Subproject commit 2457a3a1e4c7530c00890d2d2ab727538e6a06e4

diff --git a/works-tmp/temperature-converter b/works-tmp/temperature-converter
new file mode 160000 (submodule)
index 0000000..374b61a
--- /dev/null
+++ b/works-tmp/temperature-converter
@@ -0,0 +1 @@
+Subproject commit 374b61a8f7fc19c1503c985f806980b8fd44ca8c