Add environment variables to docker run cmd

Author: Bruno Galindro da Costa

lib/pip.js

@@ -103,6 +103,14 @@ function installRequirements(
       cmdOptions.push('-v', `${process.env.SSH_AUTH_SOCK}:/tmp/ssh_sock:z`);
       cmdOptions.push('-e', 'SSH_AUTH_SOCK=/tmp/ssh_sock');
     }
+    if (options.dockerEnv) {
+      // Add environment variables to docker run cmd
+      options.dockerEnv.forEach(
+          function(item) {
+            cmdOptions.push('-e', item);
+          }
+      );
+    }
     if (process.platform === 'linux') {
       // Use same user so requirements folder is not root and so --cache-dir works
       cmdOptions.push('-u', `${process.getuid()}`);