made NVM_DIR and NVM_SOURCE configurable using environment variables

install.sh

@@ -2,7 +2,13 @@
 
 set -e
 
-NVM_DIR="$HOME/.nvm"
+if [ ! "$NVM_SOURCE" ]; then
+  NVM_SOURCE="https://github.com/creationix/nvm.git"
+fi
+
+if [ ! "$NVM_DIR" ]; then
+  NVM_DIR="$HOME/.nvm"
+fi
 
 if ! hash git 2>/dev/null; then
   echo >&2 "You need to install git - visit http://git-scm.com/downloads"
@@ -12,11 +18,12 @@ fi
 
 if [ -d "$NVM_DIR" ]; then
   echo "=> NVM is already installed in $NVM_DIR, trying to update"
-  echo -ne "\r=> "
-  cd $NVM_DIR && git pull
+  echo -e "\r=> \c"
+  cd "$NVM_DIR" && git pull
 else
   # Cloning to $NVM_DIR
-  git clone https://github.com/creationix/nvm.git $NVM_DIR  
+  mkdir -p "$NVM_DIR"
+  git clone "$NVM_SOURCE" "$NVM_DIR"
 fi
 
 echo