Add TypeScript linting (#827)

* add tslint, create tslint.json ruleset from .eslintrc

* remove leftover rules

* fix up meta files

scripts/ci.sh

@@ -7,19 +7,9 @@ function checkEOL {
   ./scripts/checkeol.sh
 }
 
-typecheck() {
-  yarn install -g flow-bin
-  flow --version
-  yarn run typecheck
-}
-
 lint() {
-  echo "eslint $(node_modules/.bin/eslint --version)"
-  yarn list babel-eslint
-  REPO_URL="https://raw.githubusercontent.com/ripple/javascript-style-guide"
-  curl "$REPO_URL/es6/eslintrc" > .eslintrc
-  echo "parser: babel-eslint" >> .eslintrc
-  node_modules/.bin/eslint -c .eslintrc $(git --no-pager diff --name-only -M100% --diff-filter=AM --relative $(git merge-base FETCH_HEAD origin/HEAD) FETCH_HEAD | grep "\.js$")
+  echo "tslint $(node_modules/.bin/tslint --version)"
+  yarn lint
 }
 
 unittest() {