test/py: Manual python3 fixes

- Modern pytest is more visible in telling us about parameters that we
  had not described, so describe a few more.
- ConfigParser.readfp(...) is now configparser.read_file(...)
- As part of the "strings vs bytes" conversions in Python 3, we use the
  default encoding/decoding of utf-8 but in some places tell Python to
  replace problematic conversions rather than throw a fatal error.
- Fix a typo noticed while doing the above ("tot he" -> "to the").
- As suggested by Stephen, re-alphabetize the import list
- Per Heinrich, replace how we write contents in test_fit.py

Reviewed-by: Simon Glass <sjg@chromium.org>
Tested-by: Stephen Warren <swarren@nvidia.com>
Tested-by: Simon Glass <sjg@chromium.org> [on sandbox]
Signed-off-by: Tom Rini <trini@konsulko.com>

test/py/multiplexed_log.py

@@ -51,7 +51,7 @@ class LogfileStream(object):
         """Write data to the log stream.
 
         Args:
-            data: The data to write tot he file.
+            data: The data to write to the file.
             implicit: Boolean indicating whether data actually appeared in the
                 stream, or was implicitly generated. A valid use-case is to
                 repeat a shell prompt at the start of each separate log
@@ -64,7 +64,8 @@ class LogfileStream(object):
 
         self.logfile.write(self, data, implicit)
         if self.chained_file:
-            self.chained_file.write(data)
+            # Chained file is console, convert things a little
+            self.chained_file.write((data.encode('ascii', 'replace')).decode())
 
     def flush(self):
         """Flush the log stream, to ensure correct log interleaving.
@@ -136,6 +137,10 @@ class RunAndLog(object):
             p = subprocess.Popen(cmd, cwd=cwd,
                 stdin=None, stdout=subprocess.PIPE, stderr=subprocess.STDOUT)
             (stdout, stderr) = p.communicate()
+            if stdout is not None:
+                stdout = stdout.decode('utf-8')
+            if stderr is not None:
+                stderr = stderr.decode('utf-8')
             output = ''
             if stdout:
                 if stderr:
@@ -215,7 +220,7 @@ class Logfile(object):
             Nothing.
         """
 
-        self.f = open(fn, 'wt')
+        self.f = open(fn, 'wt', encoding='utf-8')
         self.last_stream = None
         self.blocks = []
         self.cur_evt = 1