Remove obsolete methods from DriverJDBCVersion

[marschall]

The current codebase supports JDBC 4.1 and JDBC 4.2 specifications.
This means that there is no need to check if the driver supports JDBC
4.1 and lower since 4.1 is the earliest JDBC version implemented by the
driver. Therefore the methods in DriverJDBCVersion checkSupportsJDBC4
and checkSupportsJDBC41 are obsolete and can safely be removed.

Closes #61

[marschall]

com.microsoft.sqlserver.jdbc.unit.statement.StatementTest.TCStatementParam.testRowError() fails on AppVeyor with

com.microsoft.sqlserver.jdbc.SQLServerException: Lock request time out period exceeded.

but succeeds on Travis

[v-nisidh]

As Timeout timer is missing Exception is in random nature only on Appveyor, trying to close & reopen pull request.

[codecov-io]

Codecov Report

Merging #187 into dev will increase coverage by 1.53%.
The diff coverage is n/a.

@@             Coverage Diff              @@
##                dev     #187      +/-   ##
============================================
+ Coverage     31.43%   32.96%   +1.53%     
- Complexity     1359     1436      +77     
============================================
  Files            97       97              
  Lines         23359    23180     -179     
  Branches       3881     3812      -69     
============================================
+ Hits           7342     7641     +299     
+ Misses        14589    14005     -584     
- Partials       1428     1534     +106

Flag	Coverage Δ	Complexity Δ
#JDBC41	32.84% <ø> (+1.54%)	1427 <ø> (+78)	✅
#JDBC42	32.92% <ø> (+1.55%)	1434 <ø> (+78)	✅

Impacted Files	Coverage Δ	Complexity Δ
.../microsoft/sqlserver/jdbc/SQLServerConnection.java	39.93% <ø> (+0.22%)	206 <0> (+5)	✅
.../microsoft/sqlserver/jdbc/SQLServerDataSource.java	40.74% <ø> (-0.51%)	54 <0> (ø)
...m/microsoft/sqlserver/jdbc/SQLServerStatement.java	57.95% <ø> (-0.2%)	128 <0> (+1)
.../com/microsoft/sqlserver/jdbc/SQLServerDriver.java	73.31% <ø> (-0.09%)	25 <0> (ø)
...soft/sqlserver/jdbc/SQLServerPooledConnection.java	51.06% <ø> (+1.06%)	12 <0> (ø)	❌
.../com/microsoft/sqlserver/jdbc/SQLServerJdbc41.java	33.33% <ø> (-26.67%)	0 <0> (ø)
...oft/sqlserver/jdbc/SQLServerCallableStatement.java	13.81% <ø> (+0.39%)	39 <0> (ø)	❌
...m/microsoft/sqlserver/jdbc/SQLServerResultSet.java	24.55% <ø> (+3.31%)	172 <0> (+16)	✅
...va/com/microsoft/sqlserver/jdbc/SQLServerBlob.java	25% <ø> (+25%)	11 <0> (+11)	✅
...soft/sqlserver/jdbc/SQLServerDatabaseMetaData.java	12.72% <ø> (-0.07%)	20 <0> (ø)
... and 24 more

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