Remove NUS (PEAP) login support (#13)

* Remove PEAP submodule

* Remove PEAP build script

* Update README and CD workflow

* Update documentation

Comments out PEAP-login related info. Not deleted as we plan to bring it
back in the future.

.github/workflows/build.yml

@@ -25,8 +25,6 @@ jobs:
         run: ./build_sling.sh
       - name: build qrcode generator
         run: ./build_qrcode.sh
-      - name: build nus login program
-        run: ./build_prompt.sh
       - name: build uuidtob62
         run: ./build_uuidtob62.sh
       - name: check the outputs

.gitmodules

@@ -7,6 +7,3 @@
 [submodule "uuidtob62"]
 	path = uuidtob62
 	url = https://github.com/RichDom2185/uuidtob62.git
-[submodule "ev3dev-peap-gui-login"]
-	path = ev3dev-peap-gui-login
-	url = https://github.com/RichDom2185/ev3dev-peap-gui-login.git

README.md

@@ -7,7 +7,6 @@ If you want to know exactly how the build process works, read the [GitHub workfl
 In a nutshell:
 
 - [`build_sling.sh`](./build_sling.sh): Cross-compiles Sling and Sinter for ARM using ev3dev's cross-compilation Docker image `ev3dev/debian-stretch-cross`, with some additional dependencies added in [`Dockerfile.sling`](./Dockerfile.sling)
-- [`build_prompt.sh`](./build_prompt.sh): Cross-compiles the `nus_login` binary to allow for user login to the NUS_STU WiFi network, using ev3dev's cross-compilation Docker image `ev3dev/debian-stretch-armel-cross` with some additional dependencies added in [`Dockerfile.prompt`](./Dockerfile.prompt)
 - [`build_qrcode.sh`](./build_qrcode.sh): Cross-compiles the `show_qrcode` binary to display the QR code of the device secret on the EV3 screen
 - [`build_uuidtob62.sh`](./build_uuidtob62.sh): Cross-compiles the `uuidtob62` CLI utility to represent the device secret in a more compact format
 - [`build_image.sh`](./build_image.sh): Builds the EV3 root filesystem using [`image/Dockerfile`](image/Dockerfile) and [`image/bootstrap.sh`](image/bootstrap.sh), and then uses [Brickstrap](https://github.com/ev3dev/brickstrap) to build the final image

docs/index.md

@@ -60,9 +60,9 @@ Our customised EV3-Source image is integrated with the Source Academy. You can s
 
 ### 2.2 Connecting the EV3 to WiFi
 
-The preferred method of connecting the EV3 to the internet is via WiFi. This can be done in the one of the following ways:
+The preferred method of connecting the EV3 to the internet is via WiFi. This can be done in the ~~one of~~ the following way~~s~~:
 
-#### Connecting to NUS_STU
+<!-- #### Connecting to NUS_STU
 
 Only one person per team needs to do this:
 
@@ -99,17 +99,17 @@ Only one person per team needs to do this:
 
    ![](images/ev3/wifi.png)
 
-That's it! If your credentials are correct, the EV3 should connect to NUS_STU within a few seconds. If the EV3 does not detect the WiFi network, you may want to select "Start Scan" **once** to force a refresh.
+That's it! If your credentials are correct, the EV3 should connect to NUS_STU within a few seconds. If the EV3 does not detect the WiFi network, you may want to select "Start Scan" **once** to force a refresh. -->
 
 #### Connecting to a personal hotspot
 
-If you are not within range of NUS_STU, or if you prefer to use your own network, you can do the following instead:
+<!-- If you are not within range of NUS_STU, or if you prefer to use your own network, you can do the following instead: -->
 
 1. From the main menu, select 'Wireless and Networks'
 1. Select 'Wi-Fi' and ensure it is powered on
 1. Select your network and connect to it. If your network is secured with a password, the EV3 will prompt you for one when you press 'Connect'
 
-**Note:** NUS Wi-Fi may be having connection issues from time to time. If you see a "Status: Failed" message in the Wi-Fi menu entry for NUS_STU, try toggling the Wi-Fi off and on again. It may take multiple attempts at this. Alternatively, you may use a personal hotspot or other connection methods.
+<!-- **Note:** NUS Wi-Fi may be having connection issues from time to time. If you see a "Status: Failed" message in the Wi-Fi menu entry for NUS_STU, try toggling the Wi-Fi off and on again. It may take multiple attempts at this. Alternatively, you may use a personal hotspot or other connection methods. -->
 
 > **Alternative connection methods**
 >