Fix readme replacement

[sj26]

The readme replacement currently appends the array of new lines instead of the lines themselves. Modifying to concatenating the array instead of appending it fixes there problem.

Found via an error when spinning up a branch on a schema_plus_triggers:

$ schema_dev bundle install
.../schema_dev-4.2.0/lib/schema_dev/readme.rb:68:in `!~': undefined method `=~' for ["As usual:\n", "\n", "```ruby\n", "gem \"<%= gem_name %>\"                # in a Gemfile\n", "gem.add_dependency \"<%= gem_name %>\" # in a .gemspec\n", "```\n"]:Array (NoMethodError)

  before = lines.take_while { |line| line !~ pattern }
                                          ^^
  from .../schema_dev-4.2.0/lib/schema_dev/readme.rb:68:in `block in replace_block'
  ...

Before

Without this, the first replacement causes lines to contain an array instead of only strings:

[
  ...,
  "<!-- SCHEMA_DEV: TEMPLATE #{key} - begin -->\n",
  "<!-- These lines are auto-inserted from a schema_dev template -->\n",
  [
    "template line 1\n",
    "template line 2\n",
    ...
  ],
  "\n",
  "<!-- SCHEMA_DEV: TEMPLATE #{key} - end -->\n",
  ...
]

After

lines remains an array of strings:

[
  ...,
  "<!-- SCHEMA_DEV: TEMPLATE #{key} - begin -->\n",
  "<!-- These lines are auto-inserted from a schema_dev template -->\n",
  "template line 1\n",
  "template line 2\n",
  ...,
  "\n",
  "<!-- SCHEMA_DEV: TEMPLATE #{key} - end -->\n",
  ...
]

[coveralls]

coverage: 99.366% (+0.05%) from 99.32%
when pulling e0b3861 on sj26:fix-readme-replace-lines
into 014d579 on SchemaPlus:master.

[ronen]

Hmm I wonder why that used to work?

Thanks!