Adding makefile to bump __verion__ at 3 places.

Author: SB-PawanN

Makefile

@@ -0,0 +1,9 @@
+VERSION=$(shell cat VERSION)
+
+.PHONY: bump
+
+bump:
+	@echo $(VERSION) > VERSION
+	@python3 -c "import re; f=open('setup.py'); c=f.read(); f.close(); open('setup.py','w').write(re.sub(r\"version='[^']*'\", \"version='$(VERSION)'\", c))"
+	@python3 -c "import re; f=open('bugsnag/notifier.py'); c=f.read(); f.close(); open('bugsnag/notifier.py','w').write(re.sub(r\"'version': '[^']*'\", \"'version': '$(VERSION)'\", c))"
+	@echo "Bumped to $(VERSION)"

VERSION

@@ -0,0 +1 @@
+4.8.1

bugsnag/notifier.py

@@ -1,5 +1,5 @@
 _NOTIFIER_INFORMATION = {
     'name': 'Python Bugsnag Notifier',
     'url': 'https://github.com/bugsnag/bugsnag-python',
-    'version': '4.8.0'
+    'version': '4.8.1'
 }