Custom Plugin spec fails because migrations

I’m using the kong-vagrant with Kong 0.14 for create a custom plugin.

I created the lua files for migrations ( postgres.lua / cassandra.lua ) but when i run the test , i’m getting the following error:

➜  /kong git:(master) bin/busted -v -o gtest /kong-plugin/spec
[==========] Running tests from scanned files.
[----------] Global test environment setup.
[----------] Running tests from /kong-plugin/spec/myplugin/01-access_spec.lua
/kong-plugin/spec/myplugin/01-access_spec.lua:33: 2018/07/13 17:23:24 [warn] the 'custom_plugins' configuration property is deprecated, use 'plugins' instead
2018/07/13 17:23:24 [warn] postgres database 'kong_tests' is missing migration: (myplugin) 2018-07-13-132100_init_custom_plugin
Error: ./kong/cmd/start.lua:37: [postgres error] the current database schema does not match this version of Kong. Please run `kong migrations up` to update/initialize the database schema. Be aware that Kong migrations should only run from a single node, and that nodes running migrations concurrently will conflict with each other and might corrupt your database schema!

  Run with --v (verbose) or --vv (debug) for more details

stack traceback:
	/kong-plugin/spec/myplugin/01-access_spec.lua:33: in function </kong-plugin/spec/myplugin/01-access_spec.lua:6>

[----------] 0 tests from /kong-plugin/spec/myplugin/01-access_spec.lua (1039.40 ms total)

[----------] Global test environment teardown.
[==========] 0 tests from 1 test file ran. (1040.25 ms total)
[  PASSED  ] 0 tests.
[  ERROR   ] 1 error, listed below:
[  ERROR   ] /kong-plugin/spec/myplugin/01-access_spec.lua @ 6: Demo-Plugin: myplugin (access) setup