Qiskit-tutorials to Qiskit tutorials, drop s from requests (#796)

* Qiskit-tutorials to Qiskit tutorials, drop s from requests

* Update CONTRIBUTING.md

Author: abbycross

.github/CONTRIBUTING.md

@@ -1,6 +1,6 @@
 # Contributing
 
-If you would like to contribute to the Qiskit-tutorials, there are a number of ways to 
+If you would like to contribute to the Qiskit IQX tutorials, there are a number of ways to 
 get involved:
 
 * **Issues**: Issues can be reported with GitHub [issue
@@ -11,7 +11,7 @@ get involved:
 * **Notebooks**: If you would like to contribute a notebook, please 
   create a [fork](https://help.github.com/articles/fork-a-repo/) of the repository 
   from the `master` branch and create a 
-  [pull requests](https://help.github.com/articles/about-pull-requests) for your change.
+  [pull request](https://help.github.com/articles/about-pull-requests) for your change.
   Note that new notebooks should be placed in the relevant part of the 
   [Community](./community/) section.