Bump instances of '3.4.0' to '3.4.2'

[anonhostpi]

According to code search, there are 7 instances of v3.4.0 being referenced within the project despite the current version being v3.4.2. This was discovered on #1957

• README.md
  • Fixed by Implement Support for One-liner Installs #1957
• eng/scripts/Install-IronPython.ps1
  • Fixed by Implement Support for One-liner Installs #1957

• eng/package/choco/IronPython.nuspec

  • ironpython3/eng/package/choco/IronPython.nuspec

    Line 7 in 00fdda4

    <version>3.4.0</version>

• eng/package/nuget/IronPython.StdLib.nuspec

  • ironpython3/eng/package/nuget/IronPython.StdLib.nuspec

    Line 6 in 00fdda4

    <version>3.4.0</version>

• eng/package/nuget/IronPython.nuspec

  • ironpython3/eng/package/nuget/IronPython.nuspec

    Line 6 in 00fdda4

    <version>3.4.0</version>

• src/core/IronPython.StdLib/lib/idlelib/NEWS.txt - this is acceptable
• tests/suite/test_regressions.py - this is acceptable

[slozier]

I think the nuspec versions all get overridden when the packages are compiled. I wonder if we could put a placeholder (like 3.x) instead of make that clearer?