fix: rework tests to not output color snapshots

__tests__/__snapshots__/snapshotDiff.test.js.snap

@@ -1,23 +1,5 @@
 // Jest Snapshot v1, https://goo.gl/fbAQLP
 
-exports[`can colorize diff 1`] = `
-"Snapshot Diff:
-- First value
-+ Second value
-
-@@ -5,9 +5,10 @@
-      some
-      some
-      some
-      some
-      not
-+     so
-      very
-      long
-      script
-"
-`;
-
 exports[`can expand diff 1`] = `
 "Snapshot Diff:
 - First value

__tests__/__snapshots__/toMatchDiffSnapshot.test.js.snap

@@ -1,23 +1,5 @@
 // Jest Snapshot v1, https://goo.gl/fbAQLP
 
-exports[`proxies "colors" option(s) 1`] = `
-"Snapshot Diff:
-- First value
-+ Second value
-
-@@ -5,9 +5,10 @@
-      some
-      some
-      some
-      some
-      not
-+     so
-      very
-      long
-      script
-"
-`;
-
 exports[`proxies "contextLines" option(s) 1`] = `
 "Snapshot Diff:
 - First value

__tests__/snapshotDiff.test.js

@@ -197,7 +197,8 @@ test('can expand diff', () => {
 });
 
 test('can colorize diff', () => {
-  expect(snapshotDiff(a, b, { colors: true })).toMatchSnapshot();
+  expect(snapshotDiff(a, b)).not.toMatch('[32m-');
+  expect(snapshotDiff(a, b, { colors: true })).toMatch('[32m-');
 });
 
 test('can use contextLines on diff', () => {

__tests__/toMatchDiffSnapshot.test.js

@@ -39,14 +39,12 @@ test('works with default options', () => {
   expect(a).toMatchDiffSnapshot(b);
 });
 
-[{ expand: true }, { colors: true }, { contextLines: 0 }].forEach(
-  (options: any) => {
-    test(`proxies "${Object.keys(options).join(', ')}" option(s)`, () => {
-      // $FlowFixMe
-      expect(a).toMatchDiffSnapshot(b, options);
-    });
-  }
-);
+[{ expand: true }, { contextLines: 0 }].forEach((options: any) => {
+  test(`proxies "${Object.keys(options).join(', ')}" option(s)`, () => {
+    // $FlowFixMe
+    expect(a).toMatchDiffSnapshot(b, options);
+  });
+});
 
 test('works with custom name', () => {
   // $FlowFixMe