CI: try to fix and simplify apt setup

Run apt update to update the package cache, as this seems to be needed by
Travis now. Also reduce the package set - we don't build any deb or rpm
packages anymore. This should hopefully fix the CI build.

.travis.yml

@@ -9,7 +9,8 @@ python:
   - "3.6"
   - "pypy3"
 before_install:
-  - sudo apt install rpm dpkg-dev debhelper dh-python python3-setuptools fakeroot python3-serial python3-yaml
+  - sudo apt update
+  - sudo apt install python3-setuptools python3-serial python3-yaml
 install:
   - pip install pyusb
 script:

README.md

@@ -32,6 +32,17 @@ Features
 * Automatic power-cycling with DTR toggle or a custom shell command
 * Automatic UART protocol detection
 
+Quickstart
+----------
+
+Install stcgal (might need root/administrator privileges):
+    
+    pip3 install stcgal
+
+Call stcgal and show usage:
+
+    stcgal -h
+
 Further information
 -------------------
 

doc/FAQ.md

@@ -20,6 +20,10 @@ Interfaces that are known to not work:
 
 In general, stcgal requires accurate baud rate timings and parity support.
 
+### stcgal fails to start with the error `module 'serial' has no attribute 'PARITY_NONE'` or similar
+
+There is a module name conflict between the PyPI package 'serial' (a data serialization library) and the PyPI package 'pyserial' (the serial port access library needed by stcgal). You have to uninstall the 'serial' package (`pip3 uninstall serial`) and reinstall 'pyserial' (`pip3 install --force-reinstall pyserial`) to fix this. There is no other known solution at the moment.
+
 ### stcgal fails to recognize the MCU and is stuck at "Waiting for MCU"
 
 There are a number of issues that can result in this symptom: