added pygments to requirements

- needed for command line syntax highlighting (using bash style)

requirements/base.txt

@@ -2,6 +2,7 @@ Click==7.0
 prompt-toolkit>=3.0.2
 pyaml==19.4.1
 PyYAML==5.1.2
+Pygments>=2.6.0
 SQLAlchemy==1.3.11
 tabulate==0.8.5
 wheel>=0.35.0

setup.py

@@ -10,6 +10,7 @@ setup(
         "click",
         "prompt-toolkit",
         "pyaml",
+        "pygments",
         "sqlalchemy",
         "tabulate",
         "wheel",