Move checking aws cli to separate function

test/provisioner_file.bats

@@ -5,6 +5,7 @@
 # be sure any test cases set this.
 
 load test_helper
+verify_aws_cli
 fixtures provisioner-file
 
 setup() {

test/provisioner_shell.bats

@@ -5,6 +5,7 @@
 # be sure any test cases set this.
 
 load test_helper
+verify_aws_cli
 fixtures provisioner-shell
 
 setup() {

test/test_helper.bash

@@ -1,11 +1,13 @@
 # Let's verify that the tools we need are installed
-declare -a required=(aws)
+verify_aws_cli() {
-for cmd in "${required[@]}"; do
+    declare -a required=(aws)
+    for cmd in "${required[@]}"; do
         command -v $cmd >/dev/null 2>&1 || {
             echo "'$cmd' must be installed" >&2
             exit 1
         }
-done
+    done
+}
 
 #--------------------------------------------------------------------
 # Bats modification