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

features/core.feature

@@ -13,6 +13,19 @@ Feature: Basic reading and writing to a journal
             | But I'm better.
             """
 
+    Scenario: Printing a journal that has multiline entries
+        Given we use the config "multiline.yaml"
+        When we run "jrnl -n 1"
+        Then we should get no error
+        and the output should be
+            """
+            2013-06-09 15:39 Multiple line entry.
+            | This is the first line.
+            | This line doesn't have any ending punctuation
+            |
+            | There is a blank line above this.
+            """
+
     Scenario: Writing an entry from command line
         Given we use the config "basic.yaml"
         When we run "jrnl 23 july 2013: A cold and stormy day. I ate crisps on the sofa."
@@ -72,3 +85,11 @@ Feature: Basic reading and writing to a journal
         When we run "jrnl -on 2013-06-10 -s"
         Then the output should be "2013-06-10 15:40 Life is good."
 
+    Scenario: Invalid color configuration
+        Given we use the config "invalid_color.yaml"
+        When we run "jrnl -on 2013-06-10 -s"
+        Then the output should be
+        """
+        2013-06-10 15:40 Life is good.
+        """
+        And we should get no error