[New] Add support for NVM_AUTH_HEADER env var

Closes #3366

Co-authored-by: David Welch <david@davidwelch.co>
Co-authored-by: Andre Kradolfer <narfdre@gmail.com>

.travis.yml

@@ -32,7 +32,7 @@ before_install:
   - zsh  --version
   - dpkg -s dash | grep ^Version | awk '{print $2}'
   # install python
-  - pyenv install 2.7.18
+  - pyenv local 2.7.18 || pyenv install 2.7.18
   - pyenv local 2.7.18 || echo 'pyenv failed'
   - python -V
 install:

README.md

@@ -535,11 +535,7 @@ NVM_IOJS_ORG_MIRROR=https://iojs.org/dist nvm install iojs-v1.0.3
 To pass an Authorization header through to the mirror url, set `$NVM_AUTH_HEADER`
 
 ```sh
-export NVM_NODEJS_ORG_MIRROR=https://nodejs.org/dist
+NVM_AUTH_HEADER="Bearer secret-token" nvm install node
-export NVM_AUTH_HEADER="Bearer secret-token"
-nvm install node
-
-NVM_NODEJS_ORG_MIRROR=https://nodejs.org/dist NVM_AUTH_HEADER="Bearer secret-token" nvm install 4.2
 ```
 
 ### .nvmrc

nvm.sh

@@ -141,8 +141,8 @@ nvm_download() {
                             -e 's/-o /-O /' \
                             -e 's/-C - /-c /')
 
-    if [ -n "$NVM_AUTH_HEADER" ]; then
+    if [ -n "${NVM_AUTH_HEADER:-}" ]; then
-      ARGS="$ARGS --header \"$NVM_AUTH_HEADER\""
+      ARGS="${ARGS} --header \"${NVM_AUTH_HEADER}\""
     fi
     # shellcheck disable=SC2086
     eval wget $ARGS