Fixes for the new conditional version in 1.3

Using `when: var|failed` instead of deprecated `when_failed: var`
Fixes missing invenroty in command line

Added -i step-02/hosts where missing
Fixes style

Direct link to next step.
Fixes for the new conditional version in 1.3

Using when: var|failed
Fixes inter-steps links

Simplified style
Fixes haproxy templates [fixes #7]

haproxy spits out a warning unless some timeouts are specified in the
'defaults' section.
Fixed haproxy_stats_socket variable location ('stats socket' has to be
in global, not in a 'listen' section).
Fixes for the new conditional version in 1.3
Added variable definition

variable must be defined somehere...
Added .tags to ignore list