perform 32bit test using Python 3.7

Author: andreax79

docker/i386/Dockerfile

@@ -2,13 +2,13 @@ FROM i386/ubuntu
 
 RUN apt-get update && \
     apt-get -y install \
-    python3.6 \
-    python3.6-dev \
-    python3.6-distutils \
+    python3.7 \
+    python3.7-dev \
+    python3.7-distutils \
     curl \
     make && \
     rm -rf /var/lib/apt/lists/*
-RUN curl -sSL https://bootstrap.pypa.io/pip/3.6/get-pip.py -o get-pip.py && \
-    python3.6 get-pip.py
+RUN curl -sSL https://bootstrap.pypa.io/pip/3.7/get-pip.py -o get-pip.py && \
+    python3.7 get-pip.py
 RUN pip install pytest
 WORKDIR /app