Rename requirements-pi to requirements.common

Dockerfile.pi

@@ -27,9 +27,9 @@ RUN wget https://github.com/jjhelmus/berryconda/releases/download/v2.0.0/Berryco
  && rm Berryconda3-2.0.0-Linux-armv7l.sh
 
 # Install dependencies
-COPY requirements-pi.txt /freqtrade/
+COPY requirements-common.txt /freqtrade/
 RUN ~/berryconda3/bin/conda install -y numpy pandas scipy \
- && ~/berryconda3/bin/pip install -r requirements-pi.txt --no-cache-dir
+ && ~/berryconda3/bin/pip install -r requirements-common.txt --no-cache-dir
 
 # Install and execute
 COPY . /freqtrade/