[Tests] use rimraf over `rmdir` in teardowns

- fix test 'Running "nvm ls" should display all installed versions.': only expect versions created by this test, but no versions created by other tests

test/fast/Listing paths/teardown

@@ -1,3 +1,3 @@
-rmdir ../../../v0.0.2 >/dev/null 2>&1
-rmdir ../../../v0.0.20 >/dev/null 2>&1
-rmdir ../../../v0.12.0 >/dev/null 2>&1
+rm -rf ../../../v0.0.2
+rm -rf ../../../v0.0.20
+rm -rf ../../../v0.12.0

test/fast/Listing versions/Running "nvm ls" should display all installed versions.

@@ -28,21 +28,15 @@ nvm ls | grep iojs-v0.1.2 >/dev/null || die "iojs-v0.1.2 not found in: $(nvm ls)
 
 OUTPUT="$(nvm_ls)"
 EXPECTED_OUTPUT="v0.0.1
-v0.0.2
 v0.0.3
 v0.0.9
-v0.0.20
 iojs-v0.1.2
-v0.1.3
-v0.1.4
-v0.2.3
 v0.3.1
 v0.3.3
 v0.3.9
 iojs-v0.10.2
 v0.12.9
-v0.12.87
-v0.20.3"
+v0.12.87"
 if nvm_has_system_node || nvm_has_system_iojs; then
   EXPECTED_OUTPUT="${EXPECTED_OUTPUT}
 system"

test/fast/Listing versions/teardown

@@ -1,17 +1,16 @@
-rmdir ../../../v0.0.1 >/dev/null 2>&1
-rmdir ../../../v0.0.2 >/dev/null 2>&1
-rmdir ../../../v0.0.3 >/dev/null 2>&1
-rmdir ../../../v0.0.9 >/dev/null 2>&1
-rmdir ../../../v0.0.20 >/dev/null 2>&1
-rmdir ../../../v0.1.2 >/dev/null 2>&1
-rmdir ../../../v0.1.3 >/dev/null 2>&1
-rmdir ../../../v0.1.4 >/dev/null 2>&1
-rmdir ../../../v0.2.3 >/dev/null 2>&1
-rmdir ../../../v0.3.1 >/dev/null 2>&1
-rmdir ../../../v0.3.3 >/dev/null 2>&1
-rmdir ../../../v0.3.9 >/dev/null 2>&1
-rmdir ../../../v0.20.3 >/dev/null 2>&1
-rmdir ../../../versions >/dev/null 2>&1
-unalias nvm_has_system_node >/dev/null 2>&1
-rm -f ../../../alias/stable >/dev/null 2>&1
-rm -f ../../../alias/unstable >/dev/null 2>&1
+rm -rf ../../../v0.0.1
+rm -rf ../../../v0.0.2
+rm -rf ../../../v0.0.3
+rm -rf ../../../v0.0.9
+rm -rf ../../../v0.0.20
+rm -rf ../../../v0.1.2
+rm -rf ../../../v0.1.3
+rm -rf ../../../v0.1.4
+rm -rf ../../../v0.2.3
+rm -rf ../../../v0.3.1
+rm -rf ../../../v0.3.3
+rm -rf ../../../v0.3.9
+rm -rf ../../../v0.20.3
+rm -rf ../../../versions
+rm -f ../../../alias/stable
+rm -f ../../../alias/unstable