Use Python 3 for snippets

Fedora 28 already issues deprecation warnings, which disrupt tests.

packaging/debian/control

 Build-Depends:
  debhelper (>= 9),
  python,
- libpython2.7-minimal,
- libpython2.7-stdlib,
+ libpython3.5-minimal,
+ libpython3.5-stdlib,
  shellfu (>= 0.10),
  shellfu (<< 0.11),
  shellfu-bash,
 Architecture: all
 Depends:
  python,
- libpython2.7-minimal,
- libpython2.7-stdlib,
+ libpython3.5-minimal,
+ libpython3.5-stdlib,
  shellfu (>= 0.10),
  shellfu (<< 0.11),
  shellfu-bash,

packaging/template.spec

 BuildArch:  noarch
 BuildRequires: %shellfu_req
 BuildRequires: perl
-BuildRequires: python
-BuildRequires: python-libs
+BuildRequires: python3
+BuildRequires: python3-libs
 BuildRequires: shellfu-bash-pretty
 
 Requires: %shellfu_req
 Requires: perl
-Requires: python
-Requires: python-libs
+Requires: python3
+Requires: python3-libs
 Requires: shellfu-bash
 Requires: shellfu-bash-pretty
 %description

src/uripecker.sh.skel

         echo 'import sys'
         echo
         echo 'for uri in re.findall(os.environ["URI_RE"], sys.stdin.read()):'
-        echo '    print uri'
+        echo '    print(uri)'
     )
-    URI_RE=$uri_re python -c "$py_code"
+    URI_RE=$uri_re python3 -c "$py_code"
 }
 
 __uripecker__minimize() {
     local query=$1
     debug -v query
     #shellcheck disable=SC2028
-    python -c "$(
-        echo 'import urllib'
+    LC_ALL=en_US.UTF-8 python3 -c "$(
+        echo 'import urllib.parse'
         echo 'import sys'
-        echo 'print urllib.quote_plus(sys.argv[1])'
+        echo 'print(urllib.parse.quote_plus(sys.argv[1]))'
     )" "$query"
+    #FIXME: There should be proper way w/o touching LC_ALL
 }
 
 #shellfu module-version=__MKIT_PROJ_VERSION__