Add basic code coverage requirements

Author: EvanHahn

.gitignore

@@ -1,3 +1,5 @@
 /node_modules/
 
 /dist/
+
+/coverage/

.prettierignore

@@ -0,0 +1 @@
+/coverage/

jest.config.js

@@ -1,7 +1,15 @@
 module.exports = {
+  collectCoverage: true,
+  coverageThreshold: {
+    global: {
+      branches: 50,
+      functions: 100,
+      lines: 50,
+    },
+  },
   errorOnDeprecated: true,
   preset: "ts-jest",
   resetMocks: true,
   testEnvironment: "node",
-  testPathIgnorePatterns: ["<rootDir>/node_modules/", "<rootDir>/dist/"],
+  testRegex: "/test/.*\\.test\\.[jt]s",
 };