Pretty print journal entries (#692)

* Pretty print journal entry titles and dates.

Changes appearance of all jrnl viewing commands, such as $ jrnl --short and
$ jrnl -n {NUM}.

Fix #508

* Removed extra newline at end of title

* Use ansiwrap to properly wrap strings with ANSI escapes

* Add ansiwrap to pyproject.toml

* Allow configuration of colors

- Replaced raw escapes with colorama
- Added colors key to config
- Add checks for validity of color values

* Add color configuration documentation

* Fix broken tests due to config change

* Add tests for colors in configs

- Identifying invalid color configs
- Upgrading config from no colors -> colors

* Add colorama dependency for all platforms

* Allow users to disable colorization of output

* Update poetry.lock

* Add tag and body color customization options

* Fix colorization of tags in title and body

* Updated tests to use no color by default

* Change pass to continue in verify_config()

* Better style in Entry.py

* Reduce code duplication for tag highlighting

- Breaks "unreadable date" regression test for unknown reason

* Properly colorize tags and print body

* Reformatting and clean up

* Replace list comprehension with generator

* Handle invalid colors by not using a color

* Process ANSI escapes properly with behave

* Fixed the 'spaces after tags directly next to punctuation' bug

Broke processing of tags next to any punctuation at all

* Closer to working tag colorization but not perfect

* Add tests printing for multiline journals

Fix #717

* Correctly indent first line of multiline entry

* Add test for multiline entries with tags

* Remove redundant UNICODE flag

* Progress towards proper tag colorization and body formatting

* Fix newline colorization bug

Debug code left intact since there are more bugs to fix :/

* And now the space just ends up before the tag instead of after it

* Fix assertion syntax warning

* Moved tag test to tagging.feature file

* Strip out debug code and clean up

* Bold datetimes in title

* Bold all titles

Fix #720

* Remove PY2 and PY3 constants

* Fix regression in features/steps/core.py

* Fix tag_regex

* Remove redundant re.UNICODE flag

* Remove extraneous code

docs/advanced.md

@@ -35,8 +35,9 @@ and can be edited with a plain text editor.
   - `highlight`
     if `true`, tags will be highlighted in cyan.
   - `linewrap`
-    controls the width of the output. Set to `false` if you don't
-    want to wrap long lines.
+    controls the width of the output. Set to `false` if you don't want to wrap long lines.
+  - `colors`
+    dictionary that controls the colors used to display journal entries. It has two subkeys, which are: `date` and `title`. Current valid values are: `BLACK`, `RED`, `GREEN`, `YELLOW`, `BLUE`, `MAGENTA`, `CYAN`, and `WHITE`. `colorama.Fore` is used for colorization, and you can find the [docs here](https://github.com/tartley/colorama#colored-output). To disable colored output, set the value to `NONE`. If you set the value of any color subkey to an invalid color, no color will be used.
 
 !!! note
     Although it seems intuitive to use the `#`