v0.33.7

Fixes
 - fix unassigned variable (#1665, #1664)
 - Fix for $path used by zsh (#1669)
 - `set -u`: ensure `NVM_USE_OUTPUT` is always set (#1671)
 - `install.sh`: Fix a bug that block that installation of node in install.sh (#1676)
 - `nvm install-latest-npm`: fix node 4-4.6

Documentation
 - Make `nvm cache clear` message less ambiguous (#1644)
 - Added missing piece (#1658)

nvm.sh

@@ -3383,7 +3383,7 @@ nvm() {
       NVM_VERSION_ONLY=true NVM_LTS="${NVM_LTS-}" nvm_remote_version "${PATTERN:-node}"
     ;;
     "--version" )
-      nvm_echo '0.33.6'
+      nvm_echo '0.33.7'
     ;;
     "unload" )
       nvm deactivate >/dev/null 2>&1