Replace main() with unit test. This converts the project from a binar…

…y to a library

src/lib.rs

@@ -0,0 +1,13 @@
+extern crate base64;
+extern crate ring;
+
+mod string_encryption_key_based_symmetric;
+
+#[cfg(test)]
+mod tests {
+    #[test]
+    fn it_works() {
+        // This test simply simply runs all the examples to ensure that they compile and work.
+        ::string_encryption_key_based_symmetric::main();
+    }
+}