Make release helper more robust

* check for bumpversion and error out if missing
* drop bumpversion dependency from .deb

Change-Id: Ide04d4c1ba20426bdf9531e25b462eda9418858a
Related: OS#1861

debian/control

@@ -281,7 +281,6 @@ Architecture: any
 Multi-Arch: same
 Section: libdevel
 Depends: libosmocore,
-         bumpversion,
          libtalloc-dev,
          ${misc:Depends}
 Description: Development headers for Open Source MObile COMmunications CORE library

osmo-release.mk

@@ -2,6 +2,7 @@ ifndef REL
 	REL := patch
 endif
 
+BUMPVER := $(shell bumpversion)
 NEW_VER := $(shell bumpversion --list --current-version $(VERSION) $(REL) --allow-dirty | awk -F '=' '{ print $$2 }')
 LIBVERS := $(shell git grep -n LIBVERSION | grep  '=' | grep am | grep -v LDFLAGS)
 MAKEMOD := $(shell git diff -GLIBVERSION --stat | grep Makefile.am)
@@ -9,6 +10,10 @@ ISODATE := $(shell date -I)
 
 release:
 
+ifeq ($(BUMPVER),)
+	@$(error Unable to find 'bumpversion' command.)
+endif
+
 ifeq ($(NEW_VER),)
 	@$(error Please fix versioning to match http://semver.org/ spec (current is $(VERSION)) before proceeding.)
 endif