💅 Clean up version sorting and add test

test/test_helper.bash

@@ -119,7 +119,7 @@ path_without() {
     if [ "$found" != "${RBENV_ROOT}/shims" ]; then
       alt="${RBENV_TEST_DIR}/$(echo "${found#/}" | tr '/' '-')"
       mkdir -p "$alt"
-      for util in bash head cut readlink greadlink; do
+      for util in bash head cut readlink greadlink sed sort awk; do
         if [ -x "${found}/$util" ]; then
           ln -s "${found}/$util" "${alt}/$util"
         fi

test/versions.bats

@@ -56,15 +56,19 @@ OUT
 @test "multiple versions" {
   stub_system_ruby
   create_version "1.8.7"
-  create_version "1.9.3"
+  create_version "1.9.3-p13"
+  create_version "1.9.3-p2"
   create_version "2.2.10"
   create_version "2.2.3"
+  create_version "2.2.3-pre.2"
   run rbenv-versions
   assert_success
   assert_output <<OUT
 * system
   1.8.7
-  1.9.3
+  1.9.3-p2
+  1.9.3-p13
+  2.2.3-pre.2
   2.2.3
   2.2.10
 OUT