Use curl instead of wget in install_vault.sh.

curl is installed by default on many systems

Original pull request: gh-505.

README.adoc

@@ -78,7 +78,7 @@ If you'd rather like the latest snapshots of the upcoming major version, use our
 To get started with Vault and this guide you need a
 *NIX-like operating systems that provides:
 
-* `wget`, `openssl` and `unzip`
+* `curl`, `openssl` and `unzip`
 * at least Java 8 and a properly configured `JAVA_HOME` environment variable
 
 *Install Vault*

src/test/bash/install_vault.sh

@@ -104,12 +104,12 @@ function download() {
     # install Vault
     say "Downloading Vault from ${VAULT_URL}"
 
-    verbose "wget ${VAULT_URL} -O ${VAULT_FILE}"
+    verbose "curl ${VAULT_URL} --output ${VAULT_FILE}"
 
     if [[ ${VERBOSE} == true ]]; then
-      wget "${VAULT_URL}" -O "${VAULT_FILE}"
+      curl "${VAULT_URL}" -vs --output "${VAULT_FILE}"
     else
-      wget "${VAULT_URL}" -q -O "${VAULT_FILE}"
+      curl "${VAULT_URL}" -s --output "${VAULT_FILE}"
     fi
 
     if [[ $? != 0 ]]; then