spec: add postgres_password to fsc build

We missed adding the postgres password to fsc build.
This adds that env var and propagates the results.

FSC build working with changes:
https://jenkins.inst-ci.net/job/Canvas/job/test-suites/job/flakey-spec-catcher/4785/

flag = none
closes: CCI-355

Change-Id: Ia9eea1ed9c42f1946b9c840472d1e51383987e7f
Reviewed-on: https://gerrit.instructure.com/c/canvas-lms/+/235737
Tested-by: Service Cloud Jenkins <svc.cloudjenkins@instructure.com>
Reviewed-by: Jacob Powell <spowell@instructure.com>
Reviewed-by: Rex Fleischer <rfleischer@instructure.com>
Reviewed-by: Derek Bender <djbender@instructure.com>
QA-Review: Jacob Powell <spowell@instructure.com>
Product-Review: James Butters <jbutters@instructure.com>

Jenkinsfile

@@ -335,7 +335,7 @@ pipeline {
             echo 'adding Flakey Spec Catcher'
             stages['Flakey Spec Catcher'] = {
               skipIfPreviouslySuccessful("flakey-spec-catcher") {
-                wrapBuildExecution('test-suites/flakey-spec-catcher', buildParameters, false, "")
+                wrapBuildExecution('test-suites/flakey-spec-catcher', buildParameters, true, "")
               }
             }
           }

Jenkinsfile.selenium.flakey_spec_catcher

@@ -133,6 +133,7 @@ pipeline {
     // fsc errors when running specs from gems.
     // until we figure out how to run them, we should ignore them
     FSC_IGNORE_FILES = "gems/.*/spec/"
+    POSTGRES_PASSWORD = 'sekret'
   }
 
   stages {