Log Message:
Update ruby-net-ssh to 2.10.1.rc2.

## 1.8.1

  * Change license to MIT, thanks to all the patient contributors who gave
    their permissions.

## 1.8.0

  * add SSHKit::Backend::ConnectionPool#close_connections
    [PR #285](https://github.com/capistrano/sshkit/pull/285)
    @akm
  * Clean up rubocop lint warnings
    [PR #275](https://github.com/capistrano/sshkit/pull/275)
    @cshaffer
    * Prepend unused parameter names with an underscore
    * Prefer “safe assignment in condition”
    * Disambiguate regexp literals with parens
    * Prefer `sprintf` over `String#%`
    * No longer shadow `caller_line` variable in `DeprecationLogger`
    * Rescue `StandardError` instead of `Exception`
    * Remove useless `private` access modifier in `TestAbstract`
    * Disambiguate block operator with parens
    * Disambiguate between grouped expression and method params
    * Remove assertion in `TestHost#test_assert_hosts_compare_equal` that \ 
compares something with itself
  * Export environment variables and execute command in a subshell.
    [PR #273](https://github.com/capistrano/sshkit/pull/273)
    @kuon
  * Introduce `log_command_start`, `log_command_data`, `log_command_exit` \ 
methods on `Formatter`
    [PR #257](https://github.com/capistrano/sshkit/pull/257)
    @robd
    * Deprecate `@stdout` and `@stderr` accessors on `Command`
  * Add support for deprecation logging options.
    [README](README.md#deprecation-warnings),
    [PR #258](https://github.com/capistrano/sshkit/pull/258)
    @robd
  * Quote environment variable values.
    [PR #250](https://github.com/capistrano/sshkit/pull/250)
    @Sinjo - Chris Sinjakli
  * Simplified formatter hierarchy.
    [PR #248](https://github.com/capistrano/sshkit/pull/248)
    @robd
    * `SimpleText` formatter now extends `Pretty`, rather than duplicating.
  * Hide ANSI color escape sequences when outputting to a file.
    [README](README.md#output-colors),
    [Issue #245](https://github.com/capistrano/sshkit/issues/245),
    [PR #246](https://github.com/capistrano/sshkit/pull/246)
    @robd
    * Now only color the output if it is associated with a tty,
      or the `SSHKIT_COLOR` environment variable is set.
  * Removed broken support for assigning an `IO` to the `output` config option.
    [Issue #243](https://github.com/capistrano/sshkit/issues/243),
    [PR #244](https://github.com/capistrano/sshkit/pull/244)
    @robd
    * Use `SSHKit.config.output = SSHKit::Formatter::SimpleText.new($stdin)` instead
  * Added support for `:interaction_handler` option on commands.
    [PR #234](https://github.com/capistrano/sshkit/pull/234),
    [PR #242](https://github.com/capistrano/sshkit/pull/242)
    @robd
  * Removed partially supported `TRACE` log level.
    \ 
[2aa7890](https://github.com/capistrano/sshkit/commit/2aa78905f0c521ad9f697e7a4ed04ba438d5ee78)
    @robd
  * Add support for the `:strip` option to the `capture` method and strip by \ 
default on the `Local` backend.
    [PR #239](https://github.com/capistrano/sshkit/pull/239),
    [PR #249](https://github.com/capistrano/sshkit/pull/249)
    @robd
    * The `Local` backend now strips by default to be consistent with the \ 
`Netssh` one.
    * This reverses change \ 
[7d15a9a](https://github.com/capistrano/sshkit/commit/7d15a9aebfcc43807c8151bf6f3a4bc038ce6218) \ 
to the `Local` capture API to remove stripping by default.
    * If you require the raw, unstripped output, pass the `strip: false` option: \ 
`capture(:ls, strip: false)`
  * Simplified backend hierarchy.
    [PR #235](https://github.com/capistrano/sshkit/pull/235),
    [PR #237](https://github.com/capistrano/sshkit/pull/237)
    @robd
    * Moved duplicate implementations of `make`, `rake`, `test`, `capture`, \ 
`background` on to `Abstract` backend.
    * Backend implementations now only need to implement `execute_command`, \ 
`upload!` and `download!`
    * Removed `Printer` from backend hierarchy for `Local` and `Netssh` backends \ 
(they now just extend `Abstract`)
    * Removed unused `Net::SSH:LogLevelShim`
  * Removed dependency on the `colorize` gem. SSHKit now implements its own ANSI \ 
color logic, with no external dependencies. Note that SSHKit now only supports \ 
the `:bold` or plain modes. Other modes will be gracefully ignored. \ 
[#263](https://github.com/capistrano/sshkit/issues/263)
  * New API for setting the formatter: `use_format`. This differs from `format=` \ 
in that it accepts options or arguments that will be passed to the formatter's \ 
constructor. The `format=` syntax will be deprecated in a future release. \ 
[#295](https://github.com/capistrano/sshkit/issues/295)
  * SSHKit now immediately raises a `NameError` if you try to set a formatter \ 
that does not exist. [#295](https://github.com/capistrano/sshkit/issues/295)