Update README.md

Add ```pip install requests``` to install steps

README.md

@@ -33,6 +33,7 @@ Most of the framework is implemented. Most noticable is the missing analogWrite.
   curl -o get-pip.py https://bootstrap.pypa.io/get-pip.py && \
   sudo python get-pip.py && \
   sudo pip install pyserial && \
+  sudo pip install requests && \
   mkdir -p ~/Documents/Arduino/hardware/espressif && \
   cd ~/Documents/Arduino/hardware/espressif && \
   git clone https://github.com/espressif/arduino-esp32.git esp32 && \
@@ -51,6 +52,7 @@ Most of the framework is implemented. Most noticable is the missing analogWrite.
   wget https://bootstrap.pypa.io/get-pip.py && \
   sudo python get-pip.py && \
   sudo pip install pyserial && \
+  sudo pip install requests && \
   mkdir -p ~/Arduino/hardware/espressif && \
   cd ~/Arduino/hardware/espressif && \
   git clone https://github.com/espressif/arduino-esp32.git esp32 && \