insert AWS credentials directly

We can pass credentials directly in format:
aws_sercret_key_id:aws_secret_access_key

Please keep in mind this feature breaks basic security and credentials
passed this way will be accessible in job parameters.

Change-Id: I7aab051e4a9ff77aaaa93e93e8b31e9d376099dc
diff --git a/src/com/mirantis/mk/Aws.groovy b/src/com/mirantis/mk/Aws.groovy
index fc64c25..742185e 100644
--- a/src/com/mirantis/mk/Aws.groovy
+++ b/src/com/mirantis/mk/Aws.groovy
@@ -16,14 +16,28 @@
     python.setupVirtualenv(venv_path, 'python2', requirements)
 }
 
-def getEnvVars(credentials_id, region = 'us-west-2') {
+def getEnvVars(credentials, region = 'us-west-2') {
     def common = new com.mirantis.mk.Common()
 
-    def creds = common.getCredentials(credentials_id)
+    def creds
+    def username
+    def password
+
+    if (credentials.contains(':')) {
+        // we have key and secret in string (delimited by :)
+        creds = credentials.tokenized(':')
+        username = creds[0]
+        password = creds[0]
+    } else {
+        // we have creadentials_id
+        creds = common.getCredentials(credentials)
+        username = creds.username
+        password = creds.password
+    }
 
     return [
-        "AWS_ACCESS_KEY_ID=${creds.username}",
-        "AWS_SECRET_ACCESS_KEY=${creds.password}",
+        "AWS_ACCESS_KEY_ID=${username}",
+        "AWS_SECRET_ACCESS_KEY=${password}",
         "AWS_DEFAULT_REGION=${region}"
     ]
 }