* Validate current node version (#19154)
* feat(12976): node version validation at runtime.
* refact(12976): move the code into a static utilities class.
* test(12976): added first test case using jest.
* test(12976): added test cases for node_version.
* feat(12976): create setup env node to bootstrap babel, ts-node and node version validator.
* refact(12976): migrated node version code from es6 to es5.
* feat(12976): node version validation at runtime.
* refact(12976): move the code into a static utilities class.
* test(12976): added first test case using jest.
* test(12976): added test cases for node_version.
* feat(12976): create setup env node to bootstrap babel, ts-node and node version validator.
* refact(12976): migrated node version code from es6 to es5.
* fix(12976): remove one level from ts node register cache directory link.
* chore(12976): added caret to semver dependecy in order to support minor versions.
* refact(12976): small change from named import to default import on node version validator.
* refact(12976): removed ts_node_register and add the code to babel_register.
* feat(12976): split eslint config in order to properly support files built to run before and after node version validator. refact(12976): convert script files to es5 code. refact(12976): delete inline eslint configs from node version check related files.
* refact(12976): remove ts node register file.
* refact(12976): completely port setup_node_env to es5.
* refact(12976): remove babel_register invokation from external dependencies in scripts.
* refact(12976): move node_version code directly into node_version_validator inside setup_node_env folder.
* refact(12976): only node version validator for kbn script.
* Fix check_file_casing babel_register reference (#19457)
* chore(12976): fixed license headers on new files.
* [babel] create babel-preset and babel-register modules
* [babel-preset] add comments to babel-preset-env.target choices
* [babel-preset] use more normal BUILT_WITH_BABEL signal
* [babel-register] extended comment about filtering ./src in dist
* [babel-preset] stage of class properties has changed, sorta
(cherry picked from commit 48d35f81fd)
* [functional_test_runner] replace functional testing tools with custom/pluggable solution
* [functional_test_runner] Convert unit tests to commonjs format
* [functional_test_runner] Fix dashboard test in wrong mode
* [functional_test_runner] Add dashboardLandingPage test subject
* [functional_test_runner] Get Visualize page object
* [functional_test_runner] Fix outdated references
* [functional_test_runner] Fix more outdated refs
* [functional_test_runner] Remove duplicate tests
* [functional_test_runner] Improve test readability
* [functional_test_runner] 😞 So many duplicate methods
* [functional_test_runner] Move mgmt `before` outside toplevel describe
* [functional_test_runner] Settings page obj missing methods
* [functional_test_runner] Add improvements from @gammon
* [functional_test_runner] Fix return statements in async funcs
* [functional_test_runner] Move before() to correct scope
* [functional_test_runner] Add after() hooks to remove index patterns
* [functional_test_runner] Attempt to fix vertical bar chart tests
* [functional_test_runner] Clean up
* [functional_test_runner] Reinstate unit tests
* [functional_test_runner] Set default loglevel back to info
* [functional_test_runner] Replace `context`s with `describe`s
* [functional_test_runner] Better error handling
* [functional_test_runner] Add in new Tile Map tests
* Incorporate changes from master
* [functional_test_runner] validate that every test file has a single top-level suite
* Update contributing doc with link to full doc
* [docs] Spelling and grammar fixes
* docs: writing and running functional tests
* [docs] Move plugin doc to plugin area
* [docs] Housekeeping. Doc in wrong place
* [docs] Remove dup doc file
* [grunt] Only run mocha_setup when running tests, not every grunt task
