Fixed typos and grammar errors for CONTRIBUTING.md.

Relative dialyzer paths

Fixes issue #880

May break backwards compat with projects that manually called the
dialyzer formatter, but we never documented or expected this to be
exposed.

This allows to reuse the code for any provider that formats source files
out to the user.

The option to configure it does remain compiler-centric for backwards
compatibility

Fixed missing hypens, and improper wording in README.md

[FEATURE] Add .editorconfig Settings.

https://github.com/erlang/rebar3/issues/1443

upgrade erlware_commons to 1.0.0 for OTP20 support

upgrade relx to fixed hex package 3.22.2

add option to pass args to user_drv for custom shells

Bump relx to 3.22.1

Type specifications and edocs improvements

Improve merge of command line options and config options in CT

refine eunit test detection

application modules will be added to the eunit test set automatically, no
need to consider them for inclusion in the test set separately

... before calling erlang:function_exported(ct_testspec,get_tests,1).

stops the eunit provider from filtering out test modules based on the
file extension. previously, it was hardcoded to expect all test files
ended in `.erl`. this change allows for endings like `.lfe` and `.beam`

Parse given test specs and add all spec- and suite directories as
extra_src_dirs in order to ensure that all these directories are
copied to the _build area and the suites are compiled.

Specs located in the project- or app root are explicitly copied to the
_build area in order to avoid recursive copying of the complete
directory tree.

shell: don't crash apps that use release version operators

the releases website has changed

Like for instance: {app, "0.1.0", '='}

Add rebar3.crashdump to gitignore template

Fix regex match for ignored file

add `get-deps` provider

The regex mistakenly matched too many files (any character followed by
an underscore) rather than only files starting in '._'

This properly escapes the expressions to work in all cases.

This is a bugfix. It makes sure that the given path to a testspec is
translated so common_test will pick the spec from the _build
directory, and not from the source tree.

Update THANKS

This is necessary in order to automatically get the testspec included
as an artifact (i.e. copied to the _build dir) in the case when it is
stored in another directory than 'test'.

Select git clone command by git version

The option --single-branch was introduced in git version 1.7.10 and
thus rebar3 cannot fetch git dependencies on systems where earlier
git versions are install.

This commit will select other git clone commands if an earlier git
version is detected. If the git version cannot be determined rebar3
falls back on the previous behavior and uses --single-branch.

a no-op provider that depends on lock that is slightly more discoverable and user friendly

Bug: option 'spec' is not specifically handled when merging options
from the command line with options from rebar.config. Due to this, if
the config specifies a 'spec', then this will take precedence over any
'dir' and/or 'suite' on the command line.

This commit takes special care of all options that can be used to
select tests - meaning that if any of the options 'spec', 'dir',
'suite', 'group' or 'case' are specified on the command line, then all
'spec', 'dir', 'suite', 'group' and 'case' options in rebar.config
will be ignored.

Restrict regexp to match on files starting with '._'