Remove yarn.lock, clean up .gitignore

Removed unused yarn.lock. Reduced .gitignore from 68 lines to 9 —
removed Bower, Grunt, jspm, nyc, jscoverage, node-waf and other
entries that were never relevant to this project.

Author: dasboe

.gitignore

@@ -1,67 +1,8 @@
-# Logs
-logs
-*.log
-npm-debug.log*
-yarn-debug.log*
-yarn-error.log*
-
-# Runtime data
-pids
-*.pid
-*.seed
-*.pid.lock
-
-# Directory for instrumented libs generated by jscoverage/JSCover
-lib-cov
-
-# Coverage directory used by tools like istanbul
-coverage
-
-# nyc test coverage
-.nyc_output
-
-# Grunt intermediate storage (http://gruntjs.com/creating-plugins#storing-task-files)
-.grunt
-
-# Bower dependency directory (https://bower.io/)
-bower_components
-
-# node-waf configuration
-.lock-wscript
-
-# Compiled binary addons (https://nodejs.org/api/addons.html)
-build/Release
-
-# Dependency directories
 node_modules/
-jspm_packages/
-
-# TypeScript v1 declaration files
-typings/
-
-# Optional npm cache directory
-.npm
-
-# Optional eslint cache
-.eslintcache
-
-# Optional REPL history
-.node_repl_history
-
-# Output of 'npm pack'
+*.log
 *.tgz
-
-# Yarn Integrity file
-.yarn-integrity
-
-# dotenv environment variables file
-.env
-
-# next.js build output
-.next
-
-# .DS_Store on MAC
 .DS_Store
+.env
 
 # Playwright
 test-results/