Switched to released version of urwidgets (0.1.0)

Also, removed Python 3.6 tests as urwidgets is Python 3.7+

.github/workflows/test.yml

@@ -6,10 +6,11 @@ jobs:
   test:
     # Older Ubuntu required for testing on Python 3.6 which is not available in
     # later versions. Remove once support for 3.6 is dropped.
-    runs-on: ubuntu-20.04
+    # runs-on: ubuntu-20.04
+    runs-on: ubuntu-latest
     strategy:
       matrix:
-        python-version: ["3.6", "3.7", "3.8", "3.9", "3.10", "3.11"]
+        python-version: ["3.7", "3.8", "3.9", "3.10", "3.11"]
 
     steps:
       - uses: actions/checkout@v3

requirements.txt

@@ -2,4 +2,4 @@ requests>=2.13,<3.0
 beautifulsoup4>=4.5.0,<5.0
 wcwidth>=0.1.7
 urwid>=2.0.0,<3.0
-urwidgets=1.0.0.dev0
+urwidgets=>=0.1,<0.2

setup.py

@@ -38,7 +38,7 @@ setup(
         "beautifulsoup4>=4.5.0,<5.0",
         "wcwidth>=0.1.7",
         "urwid>=2.0.0,<3.0",
-        "urwidgets>=1.0.0.dev0",
+        "urwidgets>=0.1,<0.2",
     ],
     entry_points={
         'console_scripts': [