Eslint and Prettier weren't linting and formatting every file. (#447)

* Eslint and Prettier weren't linting and formatting every file.

* using ignore files instead of cli commands

* update eslint

Author: Janther

.eslintignore

@@ -1,2 +1,4 @@
+coverage/**/*.js
+tests/**/*.sol
 tests_config/**/*.js
 src/prettier-comments/**/*.js

.prettierignore

@@ -1,3 +1,4 @@
+coverage/**/*.js
 tests/**/*.sol
 tests_config/**/*.js
 src/prettier-comments/**/*.js