Update typos (#20)

Thanks a lot @wbowlin

Author: wbowlin

7-testing/7.2-snapshots.md

@@ -73,6 +73,6 @@ Even the Jest official documentation says this:
 
 Consider this scenario. You worked on a component, generated a snap and pushed it. Later another dev named John made some change in the component. Now the test of the snap will fail since snap still contains the code which you wrote. John will just need to update the snapshot to make the test pass. No need to update the test case, just one command: `jest --updateSnapshot` and you are done.
 
-*We recommend creating an __npm script__ for updating snaps. As you can see in the package.json of our boiler plate,  it conatains a command called "test:update". This command go through all the test cases and will update the snap whenever it is required.*
+*We recommend creating an __npm script__ for updating snaps. As you can see in the package.json of our boiler plate,  it contains a command called "test:update". This command goes through all the test cases and will update the snap whenever it is required.*
 
 __More information can be found here:__ [https://facebook.github.io/jest/docs/en/snapshot-testing.html#content](https://facebook.github.io/jest/docs/en/snapshot-testing.html#content)