Fix RTC synchronization after sleep, add many more tests

There were two issues with the tests

1. Incorrect print formats causing incorrect output.

2. The RTC driver was not waiting for the shadow registers to be
updated after sleeping, their reset values to be read.

test/Dockerfile

@@ -0,0 +1,25 @@
+FROM ubuntu:20.04
+
+RUN apt-get update && \
+    apt-get upgrade -y && \
+    DEBIAN_FRONTEND=noninteractive apt-get install -y \
+      curl \
+      sigrok-cli \
+      python3 \
+      python3-pip \
+      libncurses5 \
+    && \
+    rm -rf /var/lib/apt/lists/*
+
+RUN cd /tmp && \
+    curl 'https://www.segger.com/downloads/jlink/JLink_Linux_x86_64.deb' \
+      -H 'Content-Type: application/x-www-form-urlencoded' \
+      --data 'accept_license_agreement=accepted&submit=Download+software' \
+      --output JLink_Linux_x86_64.deb && \
+    dpkg -i ./JLink_Linux_x86_64.deb && \
+    rm ./JLink_Linux_x86_64.deb
+
+RUN pip3 install \
+      pytest \
+      pylink-square \
+      pyserial \