A slash (/) in impact function docstrings break InaSAFE

[uniomni]

Adding the following to one impact function docstring causes all impact functions to fail:

 Some stats are derived from SP2010_agregat_data_perProvinsin.dbf from
    http://dds.bps.go.id/eng/

The error message is

======================================================================
ERROR: test_filtering_of_impact_functions (__main__.Test_real_plugins)
Impact functions are filtered correctly
----------------------------------------------------------------------
Traceback (most recent call last):
  File "test_real_impact_functions.py", line 25, in test_filtering_of_impact_functions
    P = get_admissible_plugins([])
  File "/home/nielso/sandpit/inasafe-dev/impact_functions/core.py", line 463, in get_admissible_plugins
    requirelines = requirements_collect(func)
  File "/home/nielso/sandpit/inasafe-dev/impact_functions/core.py", line 143, in requirements_collect
    requires_lines[-1] = requires_lines[-1][:-1] + doc_line
IndexError: list index out of range

[uniomni]

It appears that the reason it fails is the trailing '/'

[uniomni]

Interestingly, the function requirements_collect in impact_functions/core.py reads

for cnt, line in enumerate(lines):
           
            doc_line = line.strip()
            if len(doc_line) == 0:
                continue

            if join_line and not doc_line.startswith(require_cmd):
                requires_lines[-1] = requires_lines[-1][:-1] + doc_line
            elif doc_line.startswith(require_cmd):
                requires_lines.append(doc_line[len(require_cmd) + 1:])

            join_line = doc_line[-1] == '/'

The documentation of this function states that it'll use the character '' to signify line continuation, so it looks like that
is the intention but that it isn't implemented correctly. Why this works is not clear. Will investigate.

[uniomni]

This was resolved in commit ec7a557