Upgrade Python dependencies to newer versions (#5)

- update everything in requirements.txt to latest compatible versions
- add .vscode to .gitignore

.gitignore

@@ -4,6 +4,9 @@ xkcd_settings.py
 xkcd_history.txt
 comics/
 
+# IDE
+.vscode
+
 # Byte-compiled / optimized / DLL files
 __pycache__/
 *.py[cod]

requirements.txt

@@ -1,12 +1,13 @@
-certifi==2020.4.5.1
-chardet==3.0.4
+certifi==2021.5.30
+chardet==4.0.0
 environ==1.0
-idna==2.9
-python-dateutil==2.8.0
-python-dotenv==0.13.0
-python-http-client==3.2.7
-requests==2.23.0
-sendgrid==6.3.1
-six==1.15.0
-typed-ast==1.4.1
-urllib3==1.25.9
+idna==2.10
+python-dateutil==2.8.1
+python-dotenv==0.17.1
+python-http-client==3.3.2
+requests==2.25.1
+sendgrid==6.7.0
+six==1.16.0
+starkbank-ecdsa==1.1.1
+typed-ast==1.4.3
+urllib3==1.26.5