feat: add silentInstallation option (#156)

Co-authored-by: Tony Brix <tony@brix.ninja>

README.md

@@ -111,6 +111,7 @@ can be exported from your `atomTestRunner` script for Atom to consume.
     -   `testPackages` `[default: []]` - Array of packages to include for testing. This will usually be the same packages listed in [`APM_TEST_PACKAGES`](https://github.com/atom/ci#how-do-i-install-other-atom-packages-that-my-package-build-depends-on) if using atom/ci for continuous integration  
     -   `random` `[default: false]` - Run your tests in semi-random order
     -   `seed` `[default: random]` - Sets the randomization seed if randomization is turned on
+      - `silentInstallation` `[default: false]` - Suppresses the spec helper installation messages
 
 #### Spec Helpers
 This will include Atom's [spec-helper](http://flight-manual.atom.io/hacking-atom/sections/writing-specs/#custom-matchers).

lib/create-runner.js

@@ -76,6 +76,7 @@ const defaults = {
 	testPackages: [],
 	random: false,
 	seed: null,
+	silentInstallation: false
 };
 
 export default function createRunner(options = {}, configFunc) {
@@ -112,7 +113,7 @@ export default function createRunner(options = {}, configFunc) {
 		const promise = new Promise(resolve => {
 			resolveWithResult = resolve;
 		});
-		const setupView = new SetupView({ headless });
+		const setupView = new SetupView({ headless, silentInstallation: options.silentInstallation });
 
 		try {
 			const jasmine = new Jasmine();

lib/setup-view.js

@@ -52,7 +52,7 @@ export default class SetupView {
 		if (version) {
 			message = `${message}@${version}`;
 		}
-		if (this.props.headless) {
+		if (this.props.headless && !this.props.silentInstallation) {
 			console.log(message);
 		}
 		return this.update({ message });