MLBEDSW-5912 - Update to Python 3.8

Change required python version from 3.6 to 3.8 in setup.py and allow
any python3 version for black pre-commit linting.

Signed-off-by: Rickard Bolin <rickard.bolin@arm.com>
Change-Id: I0d8936d92efd5137561834c0de1a3449f9e5f25c
diff --git a/.pre-commit-config.yaml b/.pre-commit-config.yaml
index 14d098b..17d3877 100644
--- a/.pre-commit-config.yaml
+++ b/.pre-commit-config.yaml
@@ -9,7 +9,7 @@
     rev: 19.10b0
     hooks:
     -   id: black
-        language_version: python3.6
+        language_version: python3
         args: [--line-length=120]
 
 -   repo: https://gitlab.com/pycqa/flake8
diff --git a/Pipfile b/Pipfile
index 24e3e5e..eaf8ff8 100644
--- a/Pipfile
+++ b/Pipfile
@@ -4,9 +4,9 @@
 verify_ssl = true
 
 [dev-packages]
-pre-commit = "*"
-pytest = "*"
-pytest-cov = "*"
+pre-commit = "2.17.0"
+pytest = "6.2.5"
+pytest-cov = "3.0.0"
 ethos-u-vela = {editable = true,path = "."}
 
 [packages]
diff --git a/setup.py b/setup.py
index 68fd28e..4982bb3 100644
--- a/setup.py
+++ b/setup.py
@@ -77,7 +77,7 @@
         "Operating System :: Microsoft :: Windows :: Windows 10",
         "Programming Language :: C",
         "Programming Language :: Python :: 3",
-        "Programming Language :: Python :: 3.6",
+        "Programming Language :: Python :: 3.8",
         "Topic :: Scientific/Engineering :: Artificial Intelligence",
         "Topic :: Software Development :: Compilers",
     ],
@@ -89,7 +89,7 @@
         "ethosu.vela.tosa",
         "ethosu.mlw_codec",
     ],
-    python_requires="~=3.6",
+    python_requires="~=3.8",
     install_requires=[
         "flatbuffers==1.12.0",
         "numpy>=1.16.6,<=1.19.5",