Update pygments

[fonsecapeter]

With the 2.3 -> 2.4 Pygments update, the old-style ansi color names were deprecated. Shellectric is currently using them and should update to the new ones.

% api get account
Traceback (most recent call last):
  File "/Users/pfonseca/.pyenv/versions/3.7.2/bin/api", line 6, in <module>
    from api_buddy.cli import run
  File "/Users/pfonseca/.pyenv/versions/3.7.2/lib/python3.7/site-packages/api_buddy/cli.py", line 4, in <module>
    from .config.preferences import load_prefs
  File "/Users/pfonseca/.pyenv/versions/3.7.2/lib/python3.7/site-packages/api_buddy/config/preferences.py", line 9, in <module>
    from ..validation.preferences import (
  File "/Users/pfonseca/.pyenv/versions/3.7.2/lib/python3.7/site-packages/api_buddy/validation/preferences.py", line 11, in <module>
    from ..utils.formatting import flat_str_dict, format_yaml_list
  File "/Users/pfonseca/.pyenv/versions/3.7.2/lib/python3.7/site-packages/api_buddy/utils/formatting.py", line 10, in <module>
    from ..config.themes import SHELLECTRIC, Shellectric
  File "/Users/pfonseca/.pyenv/versions/3.7.2/lib/python3.7/site-packages/api_buddy/config/themes.py", line 18, in <module>
    class Shellectric(Style):  # type: ignore
  File "/Users/pfonseca/.pyenv/versions/3.7.2/lib/python3.7/site-packages/pygments/style.py", line 124, in __new__
    ndef[0] = colorformat(styledef)
  File "/Users/pfonseca/.pyenv/versions/3.7.2/lib/python3.7/site-packages/pygments/style.py", line 81, in colorformat
    assert False, "wrong color format %r" % text
AssertionError: wrong color format '#ansifuchsia'